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Fix various LastIndexOf bugs when dealing with zero-length target substrings#34616

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GrabYourPitchforks merged 1 commit into from
Apr 7, 2020
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Fix various LastIndexOf bugs when dealing with zero-length target substrings #34616

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32 changes: 15 additions & 17 deletions src/libraries/Common/tests/Tests/System/StringTests.cs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -3379,7 +3379,6 @@ public static void IndexOfSequenceLengthOneValue_Char()
Assert.Equal(2, index);
Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

// A zero-length value is always "found" at the start of the span.
Comment thread
GrabYourPitchforks marked this conversation as resolved.
ReadOnlySpan<char> span = s1.AsSpan();
ReadOnlySpan<char> value = s2.AsSpan();
index = span.IndexOf(value);
Expand All@@ -3396,7 +3395,6 @@ public static void IndexOfSequenceLengthOneValueAtVeryEnd_Char()
Assert.Equal(5, index);
Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

// A zero-length value is always "found" at the start of the span.
ReadOnlySpan<char> span = s1.AsSpan();
ReadOnlySpan<char> value = s2.AsSpan();
index = span.IndexOf(value);
Expand All@@ -3413,7 +3411,6 @@ public static void IndexOfSequenceLengthOneValueJustPasttVeryEnd_Char()
Assert.Equal(-1, index);
Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

// A zero-length value is always "found" at the start of the span.
ReadOnlySpan<char> span = s1.AsSpan();
ReadOnlySpan<char> value = s2.AsSpan();
index = span.IndexOf(value);
Expand DownExpand Up@@ -3887,18 +3884,23 @@ public static void LastIndexOf_AllSubstrings(string s, string value, int startIn

if (value.Length == 0)
{
int expectedIndex = s.Length > 0 ? s.Length - 1 : 0;
int expectedStartIndex = startIndex == s.Length ? startIndex - 1 : startIndex;
int expectedStartIndex = startIndex;
if (s.Length == 0 && (startIndex == -1 || startIndex == 0))
expectedStartIndex = (value.Length == 0) ? 0 : -1;
Assert.Equal(expectedIndex, s.LastIndexOf(value, comparison));
expectedStartIndex = 0; // empty string occurs at beginning of search space
if (s.Length > 0 && startIndex < s.Length)
expectedStartIndex = startIndex + 1; // empty string occurs just after the last char included in the search space

Assert.Equal(s.Length, s.LastIndexOf(value, comparison));
Assert.Equal(expectedStartIndex, s.LastIndexOf(value, startIndex, comparison));
Assert.Equal(expectedIndex, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
Assert.Equal(s.Length, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
return;
}

if (s.Length == 0)
{
// unit test shouldn't have passed a weightless string to this routine
Assert.NotEqual(value, string.Empty, StringComparer.FromComparison(comparison));

Assert.Equal(-1, s.LastIndexOf(value, comparison));
Assert.Equal(-1, s.LastIndexOf(value, startIndex, comparison));
Assert.Equal(-1, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
Expand DownExpand Up@@ -4068,8 +4070,8 @@ public static void LastIndexOf_TurkishI_EnglishUSCulture()
}

@adamsitnikadamsitnikApr 7, 2020

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not related to your changes: IMHO this test (IndexOf_AllSubstrings) is very complex and is trying to test too many test cases at the same time. It would be better to split it into few smaller tests with self-describing names

@GrabYourPitchforksGrabYourPitchforksApr 7, 2020

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Agreed, it's a bit of a bear. Do you have recommendations for how it might naturally be split?

@adamsitnikadamsitnikApr 8, 2020

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I think that the two if blocks could become separate tests: value.Length == 0, s.Length == 0


[Theory]
[InlineData("foo", 2)]
[InlineData("hello", 4)]
[InlineData("foo", 3)]
[InlineData("hello", 5)]
[InlineData("", 0)]
public static void LastIndexOf_EmptyString(string s, int expected)
{
Expand DownExpand Up@@ -4325,13 +4327,13 @@ public static void LastIndexOfSequenceZeroLengthValue_Char()
string s1 = "0172377457778667789";
string s2 = string.Empty;
int index = s1.LastIndexOf(s2);
Assert.Equal(s1.Length - 1, index);
Assert.Equal(s1.Length, index);

// A zero-length value is always "found" at the start of the span.
// A zero-length value is always "found" at the end of the span.
ReadOnlySpan<char> span = s1.AsSpan();
ReadOnlySpan<char> value = s2.AsSpan();
index = span.LastIndexOf(value);
Assert.Equal(0, index);
Assert.Equal(span.Length, index);
}

[Fact]
Expand All@@ -4356,7 +4358,6 @@ public static void LastIndexOfSequenceLengthOneValue_Char()
int index = s1.LastIndexOf(s2);
Assert.Equal(2, index);

// A zero-length value is always "found" at the start of the span.
ReadOnlySpan<char> span = s1.AsSpan();
ReadOnlySpan<char> value = s2.AsSpan();
index = span.LastIndexOf(value);
Expand All@@ -4371,7 +4372,6 @@ public static void LastIndexOfSequenceLengthOneValueAtVeryEnd_Char()
int index = s1.LastIndexOf(s2);
Assert.Equal(5, index);

// A zero-length value is always "found" at the start of the span.
ReadOnlySpan<char> span = s1.AsSpan();
ReadOnlySpan<char> value = s2.AsSpan();
index = span.LastIndexOf(value);
Expand All@@ -4386,7 +4386,6 @@ public static void LastIndexOfSequenceLengthOneValueMultipleTimes_Char()
int index = s1.LastIndexOf(s2);
Assert.Equal(5, index);

// A zero-length value is always "found" at the start of the span.
ReadOnlySpan<char> span = s1.AsSpan();
ReadOnlySpan<char> value = s2.AsSpan();
index = span.LastIndexOf(value);
Expand All@@ -4401,7 +4400,6 @@ public static void LastIndexOfSequenceLengthOneValueJustPasttVeryEnd_Char()
int index = s1.LastIndexOf(s2);
Assert.Equal(-1, index);

// A zero-length value is always "found" at the start of the span.
ReadOnlySpan<char> span = s1.AsSpan();
ReadOnlySpan<char> value = s2.AsSpan();
index = span.LastIndexOf(value);
Expand Down
47 changes: 30 additions & 17 deletions src/libraries/System.Globalization/tests/CompareInfo/CompareInfoTests.LastIndexOf.cs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -17,7 +17,7 @@ public class CompareInfoLastIndexOfTests
public static IEnumerable<object[]> LastIndexOf_TestData()
{
// Empty strings
yield return new object[] { s_invariantCompare, "foo", "", 2, 3, CompareOptions.None, 2 };
yield return new object[] { s_invariantCompare, "foo", "", 2, 3, CompareOptions.None, 3 };
yield return new object[] { s_invariantCompare, "", "", 0, 0, CompareOptions.None, 0 };
yield return new object[] { s_invariantCompare, "", "a", 0, 0, CompareOptions.None, -1 };
yield return new object[] { s_invariantCompare, "", "", -1, 0, CompareOptions.None, 0 };
Expand All@@ -30,8 +30,8 @@ public static IEnumerable<object[]> LastIndexOf_TestData()
yield return new object[] { s_invariantCompare, "Hello", "b", 5, 5, CompareOptions.None, -1 };
yield return new object[] { s_invariantCompare, "Hello", "l", 5, 0, CompareOptions.None, -1 };

yield return new object[] { s_invariantCompare, "Hello", "", 5, 5, CompareOptions.None, 4 };
yield return new object[] { s_invariantCompare, "Hello", "", 5, 0, CompareOptions.None, 4 };
yield return new object[] { s_invariantCompare, "Hello", "", 5, 5, CompareOptions.None, 5 };
yield return new object[] { s_invariantCompare, "Hello", "", 5, 0, CompareOptions.None, 5 };

// OrdinalIgnoreCase
yield return new object[] { s_invariantCompare, "Hello", "l", 4, 5, CompareOptions.OrdinalIgnoreCase, 3 };
Expand DownExpand Up@@ -157,6 +157,32 @@ public void LastIndexOf_String(CompareInfo compareInfo, string source, string va
// Use LastIndexOf(string, string, int, int, CompareOptions)
Assert.Equal(expected, compareInfo.LastIndexOf(source, value, startIndex, count, options));

// Fixup offsets so that we can call the span-based APIs.

ReadOnlySpan<char> sourceSpan;
int adjustmentFactor; // number of chars to add to retured index from span-based APIs

if (startIndex == source.Length - 1 && count == source.Length)
{
// This idiom means "read the whole span"
sourceSpan = source;
adjustmentFactor = 0;
}
else if (startIndex == source.Length)
{
// Account for possible off-by-one at the call site
sourceSpan = source.AsSpan()[^(Math.Max(0, count - 1))..];
adjustmentFactor = source.Length - sourceSpan.Length;
}
else
{
// Bump 'startIndex' by 1, then go back 'count' chars
sourceSpan = source.AsSpan()[..(startIndex + 1)][^count..];
adjustmentFactor = startIndex + 1 - count;
}

if (expected < 0) { adjustmentFactor = 0; } // don't modify "not found" (-1) return values

if ((compareInfo == s_invariantCompare) && ((options == CompareOptions.None) || (options == CompareOptions.IgnoreCase)))
{
StringComparison stringComparison = (options == CompareOptions.IgnoreCase) ? StringComparison.InvariantCultureIgnoreCase : StringComparison.InvariantCulture;
Expand All@@ -165,20 +191,7 @@ public void LastIndexOf_String(CompareInfo compareInfo, string source, string va
Assert.Equal(expected, source.LastIndexOf(value, startIndex, count, stringComparison));

// Use int MemoryExtensions.LastIndexOf(this ReadOnlySpan<char>, ReadOnlySpan<char>, StringComparison)
// Filter differences betweeen string-based and Span-based LastIndexOf
// - Empty value handling - https://github.com/dotnet/runtime/issues/13382
// - Negative count
if (value.Length == 0 || count < 0)
return;

if (startIndex == source.Length)
{
startIndex--;
if (count > 0)
count--;
}
int leftStartIndex = (startIndex - count + 1);
Assert.Equal((expected == -1) ? -1 : (expected - leftStartIndex), source.AsSpan(leftStartIndex, count).LastIndexOf(value.AsSpan(), stringComparison));
Assert.Equal(expected - adjustmentFactor, sourceSpan.LastIndexOf(value.AsSpan(), stringComparison));
}
}

Expand Down
27 changes: 17 additions & 10 deletions src/libraries/System.Globalization/tests/CompareInfo/CompareInfoTests.cs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -310,7 +310,7 @@ public static IEnumerable<object[]> SortKey_TestData()

public static IEnumerable<object[]> IndexOf_TestData()
{
yield return new object[] { s_invariantCompare, "foo", "", 0, 0, 0 };
yield return new object[] { s_invariantCompare, "foo", "", 0, 0, 1 };
yield return new object[] { s_invariantCompare, "", "", 0, 0, 0 };
yield return new object[] { s_invariantCompare, "Hello", "l", 0, 2, -1 };
yield return new object[] { s_invariantCompare, "Hello", "l", 3, 3, 3 };
Expand All@@ -321,10 +321,14 @@ public static IEnumerable<object[]> IndexOf_TestData()

public static IEnumerable<object[]> IsSortable_TestData()
{
yield return new object[] { "", false, false };
yield return new object[] { "abcdefg", false, true };
yield return new object[] { "\uD800\uDC00", true, true };
yield return new object[] { "\uD800\uD800", true, false };
yield return new object[] { "", false };
yield return new object[] { "abcdefg", true };
yield return new object[] { "\uD800\uDC00", true };

// VS test runner for xunit doesn't handle ill-formed UTF-16 strings properly.
// We'll send this one through as an array to avoid U+FFFD substitution.

yield return new object[] { new char[] { '\uD800', '\uD800' }, false };
}

[Theory]
Expand DownExpand Up@@ -413,27 +417,30 @@ public void SortKeyMiscTest()
public void IndexOfTest(CompareInfo compareInfo, string source, string value, int startIndex, int indexOfExpected, int lastIndexOfExpected)
{
Assert.Equal(indexOfExpected, compareInfo.IndexOf(source, value, startIndex));
if (value.Length > 0)
if (value.Length == 1)
{
Assert.Equal(indexOfExpected, compareInfo.IndexOf(source, value[0], startIndex));
}

Assert.Equal(lastIndexOfExpected, compareInfo.LastIndexOf(source, value, startIndex));
if (value.Length > 0)
if (value.Length == 1)
{
Assert.Equal(lastIndexOfExpected, compareInfo.LastIndexOf(source, value[0], startIndex));
}
}

[Theory]
[MemberData(nameof(IsSortable_TestData))]
public void IsSortableTest(string source, bool hasSurrogate, bool expected)
public void IsSortableTest(object sourceObj, bool expected)
{
string source = sourceObj as string ?? new string((char[])sourceObj);
Assert.Equal(expected, CompareInfo.IsSortable(source));

bool charExpectedResults = hasSurrogate ? false : expected;
// If the string as a whole is sortable, then all chars which aren't standalone
// surrogate halves must also be sortable.

foreach (char c in source)
Assert.Equal(charExpectedResults, CompareInfo.IsSortable(c));
Assert.Equal(expected && !char.IsSurrogate(c), CompareInfo.IsSortable(c));
}

[Fact]
Expand Down
Loading
, 'i'); if (__m === '*' || __re.test(location.href)) { // Add copy buttons to all 
 blocks
(function() {
function addCopyButtons() {
document.querySelectorAll('pre code').forEach(function(codeBlock) {
if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;
codeBlock.parentElement.setAttribute('data-copy-added', 'true');
var btn = document.createElement('button');
btn.textContent = 'Copy';
btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';
btn.onmouseover = function() { this.style.opacity = '1'; };
btn.onmouseout = function() { this.style.opacity = '0.7'; };
btn.onclick = function() {
navigator.clipboard.writeText(codeBlock.textContent).then(function() {
btn.textContent = 'Copied!';
setTimeout(function() { btn.textContent = 'Copy'; }, 1500);
});
};
codeBlock.parentElement.style.position = 'relative';
codeBlock.parentElement.appendChild(btn);
});
}
addCopyButtons();
// Re-run on dynamic content
var observer = new MutationObserver(addCopyButtons);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '
Fix various LastIndexOf bugs when dealing with zero-length target substrings by GrabYourPitchforks · Pull Request #34616 · dotnet/runtime · GitHub
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Fix various LastIndexOf bugs when dealing with zero-length target substrings#34616

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 Merged

GrabYourPitchforks
merged 1 commit into

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Apr 7, 2020
 Merged


Fix various LastIndexOf bugs when dealing with zero-length target substrings
#34616
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32 changes: 15 additions & 17 deletions
src/libraries/Common/tests/Tests/System/StringTests.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -3379,7 +3379,6 @@ public static void IndexOfSequenceLengthOneValue_Char()
 Assert.Equal(2, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
Comment thread
GrabYourPitchforks marked this conversation as resolved.

 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand All@@ -3396,7 +3395,6 @@ public static void IndexOfSequenceLengthOneValueAtVeryEnd_Char()
 Assert.Equal(5, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand All@@ -3413,7 +3411,6 @@ public static void IndexOfSequenceLengthOneValueJustPasttVeryEnd_Char()
 Assert.Equal(-1, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand DownExpand Up@@ -3887,18 +3884,23 @@ public static void LastIndexOf_AllSubstrings(string s, string value, int startIn

 if (value.Length == 0)
 {
 int expectedIndex = s.Length > 0 ? s.Length - 1 : 0;
 int expectedStartIndex = startIndex == s.Length ? startIndex - 1 : startIndex;
 int expectedStartIndex = startIndex;
 if (s.Length == 0 && (startIndex == -1 || startIndex == 0))
 expectedStartIndex = (value.Length == 0) ? 0 : -1;
 Assert.Equal(expectedIndex, s.LastIndexOf(value, comparison));
 expectedStartIndex = 0; // empty string occurs at beginning of search space
 if (s.Length > 0 && startIndex < s.Length)
 expectedStartIndex = startIndex + 1; // empty string occurs just after the last char included in the search space

 Assert.Equal(s.Length, s.LastIndexOf(value, comparison));
 Assert.Equal(expectedStartIndex, s.LastIndexOf(value, startIndex, comparison));
 Assert.Equal(expectedIndex, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
 Assert.Equal(s.Length, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
 return;
 }

 if (s.Length == 0)
 {
 // unit test shouldn't have passed a weightless string to this routine
 Assert.NotEqual(value, string.Empty, StringComparer.FromComparison(comparison));

 Assert.Equal(-1, s.LastIndexOf(value, comparison));
 Assert.Equal(-1, s.LastIndexOf(value, startIndex, comparison));
 Assert.Equal(-1, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
Expand DownExpand Up@@ -4068,8 +4070,8 @@ public static void LastIndexOf_TurkishI_EnglishUSCulture()
 }
@adamsitnikadamsitnikApr 7, 2020

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not related to your changes: IMHO this test (IndexOf_AllSubstrings) is very complex and is trying to test too many test cases at the same time. It would be better to split it into few smaller tests with self-describing names
@GrabYourPitchforksGrabYourPitchforksApr 7, 2020

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Agreed, it's a bit of a bear. Do you have recommendations for how it might naturally be split?
@adamsitnikadamsitnikApr 8, 2020

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I think that the two if blocks could become separate tests: value.Length == 0, s.Length == 0

 [Theory]
 [InlineData("foo", 2)]
 [InlineData("hello", 4)]
 [InlineData("foo", 3)]
 [InlineData("hello", 5)]
 [InlineData("", 0)]
 public static void LastIndexOf_EmptyString(string s, int expected)
 {
Expand DownExpand Up@@ -4325,13 +4327,13 @@ public static void LastIndexOfSequenceZeroLengthValue_Char()
 string s1 = "0172377457778667789";
 string s2 = string.Empty;
 int index = s1.LastIndexOf(s2);
 Assert.Equal(s1.Length - 1, index);
 Assert.Equal(s1.Length, index);

 // A zero-length value is always "found" at the start of the span.
 // A zero-length value is always "found" at the end of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
 Assert.Equal(0, index);
 Assert.Equal(span.Length, index);
 }

 [Fact]
Expand All@@ -4356,7 +4358,6 @@ public static void LastIndexOfSequenceLengthOneValue_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(2, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4371,7 +4372,6 @@ public static void LastIndexOfSequenceLengthOneValueAtVeryEnd_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(5, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4386,7 +4386,6 @@ public static void LastIndexOfSequenceLengthOneValueMultipleTimes_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(5, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4401,7 +4400,6 @@ public static void LastIndexOfSequenceLengthOneValueJustPasttVeryEnd_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(-1, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand Down

47 changes: 30 additions & 17 deletions
src/libraries/System.Globalization/tests/CompareInfo/CompareInfoTests.LastIndexOf.cs

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -17,7 +17,7 @@ public class CompareInfoLastIndexOfTests
 public static IEnumerable<object[]> LastIndexOf_TestData()
 {
 // Empty strings
 yield return new object[] { s_invariantCompare, "foo", "", 2, 3, CompareOptions.None, 2 };
 yield return new object[] { s_invariantCompare, "foo", "", 2, 3, CompareOptions.None, 3 };
 yield return new object[] { s_invariantCompare, "", "", 0, 0, CompareOptions.None, 0 };
 yield return new object[] { s_invariantCompare, "", "a", 0, 0, CompareOptions.None, -1 };
 yield return new object[] { s_invariantCompare, "", "", -1, 0, CompareOptions.None, 0 };
Expand All@@ -30,8 +30,8 @@ public static IEnumerable<object[]> LastIndexOf_TestData()
 yield return new object[] { s_invariantCompare, "Hello", "b", 5, 5, CompareOptions.None, -1 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 5, 0, CompareOptions.None, -1 };

 yield return new object[] { s_invariantCompare, "Hello", "", 5, 5, CompareOptions.None, 4 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 0, CompareOptions.None, 4 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 5, CompareOptions.None, 5 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 0, CompareOptions.None, 5 };

 // OrdinalIgnoreCase
 yield return new object[] { s_invariantCompare, "Hello", "l", 4, 5, CompareOptions.OrdinalIgnoreCase, 3 };
Expand DownExpand Up@@ -157,6 +157,32 @@ public void LastIndexOf_String(CompareInfo compareInfo, string source, string va
 // Use LastIndexOf(string, string, int, int, CompareOptions)
 Assert.Equal(expected, compareInfo.LastIndexOf(source, value, startIndex, count, options));

 // Fixup offsets so that we can call the span-based APIs.

 ReadOnlySpan<char> sourceSpan;
 int adjustmentFactor; // number of chars to add to retured index from span-based APIs

 if (startIndex == source.Length - 1 && count == source.Length)
 {
 // This idiom means "read the whole span"
 sourceSpan = source;
 adjustmentFactor = 0;
 }
 else if (startIndex == source.Length)
 {
 // Account for possible off-by-one at the call site
 sourceSpan = source.AsSpan()[^(Math.Max(0, count - 1))..];
 adjustmentFactor = source.Length - sourceSpan.Length;
 }
 else
 {
 // Bump 'startIndex' by 1, then go back 'count' chars
 sourceSpan = source.AsSpan()[..(startIndex + 1)][^count..];
 adjustmentFactor = startIndex + 1 - count;
 }

 if (expected < 0) { adjustmentFactor = 0; } // don't modify "not found" (-1) return values

 if ((compareInfo == s_invariantCompare) && ((options == CompareOptions.None) || (options == CompareOptions.IgnoreCase)))
 {
 StringComparison stringComparison = (options == CompareOptions.IgnoreCase) ? StringComparison.InvariantCultureIgnoreCase : StringComparison.InvariantCulture;
Expand All@@ -165,20 +191,7 @@ public void LastIndexOf_String(CompareInfo compareInfo, string source, string va
 Assert.Equal(expected, source.LastIndexOf(value, startIndex, count, stringComparison));

 // Use int MemoryExtensions.LastIndexOf(this ReadOnlySpan<char>, ReadOnlySpan<char>, StringComparison)
 // Filter differences betweeen string-based and Span-based LastIndexOf
 // - Empty value handling - https://github.com/dotnet/runtime/issues/13382
 // - Negative count
 if (value.Length == 0 || count < 0)
 return;

 if (startIndex == source.Length)
 {
 startIndex--;
 if (count > 0)
 count--;
 }
 int leftStartIndex = (startIndex - count + 1);
 Assert.Equal((expected == -1) ? -1 : (expected - leftStartIndex), source.AsSpan(leftStartIndex, count).LastIndexOf(value.AsSpan(), stringComparison));
 Assert.Equal(expected - adjustmentFactor, sourceSpan.LastIndexOf(value.AsSpan(), stringComparison));
 }
 }

Expand Down

27 changes: 17 additions & 10 deletions
src/libraries/System.Globalization/tests/CompareInfo/CompareInfoTests.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -310,7 +310,7 @@ public static IEnumerable<object[]> SortKey_TestData()

 public static IEnumerable<object[]> IndexOf_TestData()
 {
 yield return new object[] { s_invariantCompare, "foo", "", 0, 0, 0 };
 yield return new object[] { s_invariantCompare, "foo", "", 0, 0, 1 };
 yield return new object[] { s_invariantCompare, "", "", 0, 0, 0 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 0, 2, -1 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 3, 3, 3 };
Expand All@@ -321,10 +321,14 @@ public static IEnumerable<object[]> IndexOf_TestData()

 public static IEnumerable<object[]> IsSortable_TestData()
 {
 yield return new object[] { "", false, false };
 yield return new object[] { "abcdefg", false, true };
 yield return new object[] { "\uD800\uDC00", true, true };
 yield return new object[] { "\uD800\uD800", true, false };
 yield return new object[] { "", false };
 yield return new object[] { "abcdefg", true };
 yield return new object[] { "\uD800\uDC00", true };

 // VS test runner for xunit doesn't handle ill-formed UTF-16 strings properly.
 // We'll send this one through as an array to avoid U+FFFD substitution.

 yield return new object[] { new char[] { '\uD800', '\uD800' }, false };
 }

 [Theory]
Expand DownExpand Up@@ -413,27 +417,30 @@ public void SortKeyMiscTest()
 public void IndexOfTest(CompareInfo compareInfo, string source, string value, int startIndex, int indexOfExpected, int lastIndexOfExpected)
 {
 Assert.Equal(indexOfExpected, compareInfo.IndexOf(source, value, startIndex));
 if (value.Length > 0)
 if (value.Length == 1)
 {
 Assert.Equal(indexOfExpected, compareInfo.IndexOf(source, value[0], startIndex));
 }

 Assert.Equal(lastIndexOfExpected, compareInfo.LastIndexOf(source, value, startIndex));
 if (value.Length > 0)
 if (value.Length == 1)
 {
 Assert.Equal(lastIndexOfExpected, compareInfo.LastIndexOf(source, value[0], startIndex));
 }
 }

 [Theory]
 [MemberData(nameof(IsSortable_TestData))]
 public void IsSortableTest(string source, bool hasSurrogate, bool expected)
 public void IsSortableTest(object sourceObj, bool expected)
 {
 string source = sourceObj as string ?? new string((char[])sourceObj);
 Assert.Equal(expected, CompareInfo.IsSortable(source));

 bool charExpectedResults = hasSurrogate ? false : expected;
 // If the string as a whole is sortable, then all chars which aren't standalone
 // surrogate halves must also be sortable.

 foreach (char c in source)
 Assert.Equal(charExpectedResults, CompareInfo.IsSortable(c));
 Assert.Equal(expected && !char.IsSurrogate(c), CompareInfo.IsSortable(c));
 }

 [Fact]
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Force GitHub README to respect dark mode
(function() {
var style = document.createElement('style');
style.textContent = '
.markdown-body {
color-scheme: dark light;
}
.markdown-body pre { background: #161b22 !important; }
.markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }
.markdown-body table th, .markdown-body table td { border-color: #30363d !important; }
.markdown-body img { background: #0d1117; }
.markdown-body blockquote { border-left-color: #8b949e; }
.markdown-body hr { border-color: #30363d; }
';
document.head.appendChild(style);
})();
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Fix various LastIndexOf bugs when dealing with zero-length target substrings by GrabYourPitchforks · Pull Request #34616 · dotnet/runtime · GitHub
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Fix various LastIndexOf bugs when dealing with zero-length target substrings#34616

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Apr 7, 2020
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Fix various LastIndexOf bugs when dealing with zero-length target substrings
#34616
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32 changes: 15 additions & 17 deletions
src/libraries/Common/tests/Tests/System/StringTests.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -3379,7 +3379,6 @@ public static void IndexOfSequenceLengthOneValue_Char()
 Assert.Equal(2, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
Comment thread
GrabYourPitchforks marked this conversation as resolved.

 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand All@@ -3396,7 +3395,6 @@ public static void IndexOfSequenceLengthOneValueAtVeryEnd_Char()
 Assert.Equal(5, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand All@@ -3413,7 +3411,6 @@ public static void IndexOfSequenceLengthOneValueJustPasttVeryEnd_Char()
 Assert.Equal(-1, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand DownExpand Up@@ -3887,18 +3884,23 @@ public static void LastIndexOf_AllSubstrings(string s, string value, int startIn

 if (value.Length == 0)
 {
 int expectedIndex = s.Length > 0 ? s.Length - 1 : 0;
 int expectedStartIndex = startIndex == s.Length ? startIndex - 1 : startIndex;
 int expectedStartIndex = startIndex;
 if (s.Length == 0 && (startIndex == -1 || startIndex == 0))
 expectedStartIndex = (value.Length == 0) ? 0 : -1;
 Assert.Equal(expectedIndex, s.LastIndexOf(value, comparison));
 expectedStartIndex = 0; // empty string occurs at beginning of search space
 if (s.Length > 0 && startIndex < s.Length)
 expectedStartIndex = startIndex + 1; // empty string occurs just after the last char included in the search space

 Assert.Equal(s.Length, s.LastIndexOf(value, comparison));
 Assert.Equal(expectedStartIndex, s.LastIndexOf(value, startIndex, comparison));
 Assert.Equal(expectedIndex, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
 Assert.Equal(s.Length, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
 return;
 }

 if (s.Length == 0)
 {
 // unit test shouldn't have passed a weightless string to this routine
 Assert.NotEqual(value, string.Empty, StringComparer.FromComparison(comparison));

 Assert.Equal(-1, s.LastIndexOf(value, comparison));
 Assert.Equal(-1, s.LastIndexOf(value, startIndex, comparison));
 Assert.Equal(-1, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
Expand DownExpand Up@@ -4068,8 +4070,8 @@ public static void LastIndexOf_TurkishI_EnglishUSCulture()
 }
@adamsitnikadamsitnikApr 7, 2020

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not related to your changes: IMHO this test (IndexOf_AllSubstrings) is very complex and is trying to test too many test cases at the same time. It would be better to split it into few smaller tests with self-describing names
@GrabYourPitchforksGrabYourPitchforksApr 7, 2020

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Agreed, it's a bit of a bear. Do you have recommendations for how it might naturally be split?
@adamsitnikadamsitnikApr 8, 2020

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I think that the two if blocks could become separate tests: value.Length == 0, s.Length == 0

 [Theory]
 [InlineData("foo", 2)]
 [InlineData("hello", 4)]
 [InlineData("foo", 3)]
 [InlineData("hello", 5)]
 [InlineData("", 0)]
 public static void LastIndexOf_EmptyString(string s, int expected)
 {
Expand DownExpand Up@@ -4325,13 +4327,13 @@ public static void LastIndexOfSequenceZeroLengthValue_Char()
 string s1 = "0172377457778667789";
 string s2 = string.Empty;
 int index = s1.LastIndexOf(s2);
 Assert.Equal(s1.Length - 1, index);
 Assert.Equal(s1.Length, index);

 // A zero-length value is always "found" at the start of the span.
 // A zero-length value is always "found" at the end of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
 Assert.Equal(0, index);
 Assert.Equal(span.Length, index);
 }

 [Fact]
Expand All@@ -4356,7 +4358,6 @@ public static void LastIndexOfSequenceLengthOneValue_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(2, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4371,7 +4372,6 @@ public static void LastIndexOfSequenceLengthOneValueAtVeryEnd_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(5, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4386,7 +4386,6 @@ public static void LastIndexOfSequenceLengthOneValueMultipleTimes_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(5, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4401,7 +4400,6 @@ public static void LastIndexOfSequenceLengthOneValueJustPasttVeryEnd_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(-1, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand Down

47 changes: 30 additions & 17 deletions
src/libraries/System.Globalization/tests/CompareInfo/CompareInfoTests.LastIndexOf.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -17,7 +17,7 @@ public class CompareInfoLastIndexOfTests
 public static IEnumerable<object[]> LastIndexOf_TestData()
 {
 // Empty strings
 yield return new object[] { s_invariantCompare, "foo", "", 2, 3, CompareOptions.None, 2 };
 yield return new object[] { s_invariantCompare, "foo", "", 2, 3, CompareOptions.None, 3 };
 yield return new object[] { s_invariantCompare, "", "", 0, 0, CompareOptions.None, 0 };
 yield return new object[] { s_invariantCompare, "", "a", 0, 0, CompareOptions.None, -1 };
 yield return new object[] { s_invariantCompare, "", "", -1, 0, CompareOptions.None, 0 };
Expand All@@ -30,8 +30,8 @@ public static IEnumerable<object[]> LastIndexOf_TestData()
 yield return new object[] { s_invariantCompare, "Hello", "b", 5, 5, CompareOptions.None, -1 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 5, 0, CompareOptions.None, -1 };

 yield return new object[] { s_invariantCompare, "Hello", "", 5, 5, CompareOptions.None, 4 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 0, CompareOptions.None, 4 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 5, CompareOptions.None, 5 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 0, CompareOptions.None, 5 };

 // OrdinalIgnoreCase
 yield return new object[] { s_invariantCompare, "Hello", "l", 4, 5, CompareOptions.OrdinalIgnoreCase, 3 };
Expand DownExpand Up@@ -157,6 +157,32 @@ public void LastIndexOf_String(CompareInfo compareInfo, string source, string va
 // Use LastIndexOf(string, string, int, int, CompareOptions)
 Assert.Equal(expected, compareInfo.LastIndexOf(source, value, startIndex, count, options));

 // Fixup offsets so that we can call the span-based APIs.

 ReadOnlySpan<char> sourceSpan;
 int adjustmentFactor; // number of chars to add to retured index from span-based APIs

 if (startIndex == source.Length - 1 && count == source.Length)
 {
 // This idiom means "read the whole span"
 sourceSpan = source;
 adjustmentFactor = 0;
 }
 else if (startIndex == source.Length)
 {
 // Account for possible off-by-one at the call site
 sourceSpan = source.AsSpan()[^(Math.Max(0, count - 1))..];
 adjustmentFactor = source.Length - sourceSpan.Length;
 }
 else
 {
 // Bump 'startIndex' by 1, then go back 'count' chars
 sourceSpan = source.AsSpan()[..(startIndex + 1)][^count..];
 adjustmentFactor = startIndex + 1 - count;
 }

 if (expected < 0) { adjustmentFactor = 0; } // don't modify "not found" (-1) return values

 if ((compareInfo == s_invariantCompare) && ((options == CompareOptions.None) || (options == CompareOptions.IgnoreCase)))
 {
 StringComparison stringComparison = (options == CompareOptions.IgnoreCase) ? StringComparison.InvariantCultureIgnoreCase : StringComparison.InvariantCulture;
Expand All@@ -165,20 +191,7 @@ public void LastIndexOf_String(CompareInfo compareInfo, string source, string va
 Assert.Equal(expected, source.LastIndexOf(value, startIndex, count, stringComparison));

 // Use int MemoryExtensions.LastIndexOf(this ReadOnlySpan<char>, ReadOnlySpan<char>, StringComparison)
 // Filter differences betweeen string-based and Span-based LastIndexOf
 // - Empty value handling - https://github.com/dotnet/runtime/issues/13382
 // - Negative count
 if (value.Length == 0 || count < 0)
 return;

 if (startIndex == source.Length)
 {
 startIndex--;
 if (count > 0)
 count--;
 }
 int leftStartIndex = (startIndex - count + 1);
 Assert.Equal((expected == -1) ? -1 : (expected - leftStartIndex), source.AsSpan(leftStartIndex, count).LastIndexOf(value.AsSpan(), stringComparison));
 Assert.Equal(expected - adjustmentFactor, sourceSpan.LastIndexOf(value.AsSpan(), stringComparison));
 }
 }

Expand Down

27 changes: 17 additions & 10 deletions
src/libraries/System.Globalization/tests/CompareInfo/CompareInfoTests.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -310,7 +310,7 @@ public static IEnumerable<object[]> SortKey_TestData()

 public static IEnumerable<object[]> IndexOf_TestData()
 {
 yield return new object[] { s_invariantCompare, "foo", "", 0, 0, 0 };
 yield return new object[] { s_invariantCompare, "foo", "", 0, 0, 1 };
 yield return new object[] { s_invariantCompare, "", "", 0, 0, 0 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 0, 2, -1 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 3, 3, 3 };
Expand All@@ -321,10 +321,14 @@ public static IEnumerable<object[]> IndexOf_TestData()

 public static IEnumerable<object[]> IsSortable_TestData()
 {
 yield return new object[] { "", false, false };
 yield return new object[] { "abcdefg", false, true };
 yield return new object[] { "\uD800\uDC00", true, true };
 yield return new object[] { "\uD800\uD800", true, false };
 yield return new object[] { "", false };
 yield return new object[] { "abcdefg", true };
 yield return new object[] { "\uD800\uDC00", true };

 // VS test runner for xunit doesn't handle ill-formed UTF-16 strings properly.
 // We'll send this one through as an array to avoid U+FFFD substitution.

 yield return new object[] { new char[] { '\uD800', '\uD800' }, false };
 }

 [Theory]
Expand DownExpand Up@@ -413,27 +417,30 @@ public void SortKeyMiscTest()
 public void IndexOfTest(CompareInfo compareInfo, string source, string value, int startIndex, int indexOfExpected, int lastIndexOfExpected)
 {
 Assert.Equal(indexOfExpected, compareInfo.IndexOf(source, value, startIndex));
 if (value.Length > 0)
 if (value.Length == 1)
 {
 Assert.Equal(indexOfExpected, compareInfo.IndexOf(source, value[0], startIndex));
 }

 Assert.Equal(lastIndexOfExpected, compareInfo.LastIndexOf(source, value, startIndex));
 if (value.Length > 0)
 if (value.Length == 1)
 {
 Assert.Equal(lastIndexOfExpected, compareInfo.LastIndexOf(source, value[0], startIndex));
 }
 }

 [Theory]
 [MemberData(nameof(IsSortable_TestData))]
 public void IsSortableTest(string source, bool hasSurrogate, bool expected)
 public void IsSortableTest(object sourceObj, bool expected)
 {
 string source = sourceObj as string ?? new string((char[])sourceObj);
 Assert.Equal(expected, CompareInfo.IsSortable(source));

 bool charExpectedResults = hasSurrogate ? false : expected;
 // If the string as a whole is sortable, then all chars which aren't standalone
 // surrogate halves must also be sortable.

 foreach (char c in source)
 Assert.Equal(charExpectedResults, CompareInfo.IsSortable(c));
 Assert.Equal(expected && !char.IsSurrogate(c), CompareInfo.IsSortable(c));
 }

 [Fact]
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Highlight search terms from Google/DuckDuckGo/Bing referrer
(function() {
var ref = document.referrer;
var terms = [];
if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {
var url = new URL(ref);
var q = url.searchParams.get('q') || url.searchParams.get('p');
if (q) {
terms = q.split(/\s+/).filter(function(t) { return t.length > 2; });
}
}
if (terms.length === 0) return;
var style = document.createElement('style');
style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';
document.head.appendChild(style);
function highlight(node) {
if (node.nodeType === 3) { // text node
var text = node.textContent;
var found = false;
terms.forEach(function(term) {
var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\]\\]/g, '\\') + ')', 'gi');
if (regex.test(text)) {
found = true;
var frag = document.createDocumentFragment();
var parts = text.split(regex);
parts.forEach(function(part, i) {
if (i % 2 === 0) {
frag.appendChild(document.createTextNode(part));
} else {
var span = document.createElement('span');
span.className = 'userscript-highlight';
span.textContent = part;
frag.appendChild(span);
}
});
node.parentNode.replaceChild(frag, node);
}
});
} else if (node.nodeType === 1 && node.childNodes) { // element
var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];
if (!skipTags.includes(node.tagName)) {
Array.from(node.childNodes).forEach(highlight);
}
}
}
highlight(document.body);
// Re-highlight on dynamic content
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1 || node.nodeType === 3) highlight(node);
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Fix various LastIndexOf bugs when dealing with zero-length target substrings by GrabYourPitchforks · Pull Request #34616 · dotnet/runtime · GitHub
Skip to content
Fix various LastIndexOf bugs when dealing with zero-length target substrings#34616

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GrabYourPitchforks
merged 1 commit into

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Apr 7, 2020
 Merged


Fix various LastIndexOf bugs when dealing with zero-length target substrings
#34616
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32 changes: 15 additions & 17 deletions
src/libraries/Common/tests/Tests/System/StringTests.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -3379,7 +3379,6 @@ public static void IndexOfSequenceLengthOneValue_Char()
 Assert.Equal(2, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
Comment thread
GrabYourPitchforks marked this conversation as resolved.

 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand All@@ -3396,7 +3395,6 @@ public static void IndexOfSequenceLengthOneValueAtVeryEnd_Char()
 Assert.Equal(5, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand All@@ -3413,7 +3411,6 @@ public static void IndexOfSequenceLengthOneValueJustPasttVeryEnd_Char()
 Assert.Equal(-1, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand DownExpand Up@@ -3887,18 +3884,23 @@ public static void LastIndexOf_AllSubstrings(string s, string value, int startIn

 if (value.Length == 0)
 {
 int expectedIndex = s.Length > 0 ? s.Length - 1 : 0;
 int expectedStartIndex = startIndex == s.Length ? startIndex - 1 : startIndex;
 int expectedStartIndex = startIndex;
 if (s.Length == 0 && (startIndex == -1 || startIndex == 0))
 expectedStartIndex = (value.Length == 0) ? 0 : -1;
 Assert.Equal(expectedIndex, s.LastIndexOf(value, comparison));
 expectedStartIndex = 0; // empty string occurs at beginning of search space
 if (s.Length > 0 && startIndex < s.Length)
 expectedStartIndex = startIndex + 1; // empty string occurs just after the last char included in the search space

 Assert.Equal(s.Length, s.LastIndexOf(value, comparison));
 Assert.Equal(expectedStartIndex, s.LastIndexOf(value, startIndex, comparison));
 Assert.Equal(expectedIndex, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
 Assert.Equal(s.Length, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
 return;
 }

 if (s.Length == 0)
 {
 // unit test shouldn't have passed a weightless string to this routine
 Assert.NotEqual(value, string.Empty, StringComparer.FromComparison(comparison));

 Assert.Equal(-1, s.LastIndexOf(value, comparison));
 Assert.Equal(-1, s.LastIndexOf(value, startIndex, comparison));
 Assert.Equal(-1, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
Expand DownExpand Up@@ -4068,8 +4070,8 @@ public static void LastIndexOf_TurkishI_EnglishUSCulture()
 }
@adamsitnikadamsitnikApr 7, 2020

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not related to your changes: IMHO this test (IndexOf_AllSubstrings) is very complex and is trying to test too many test cases at the same time. It would be better to split it into few smaller tests with self-describing names
@GrabYourPitchforksGrabYourPitchforksApr 7, 2020

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Agreed, it's a bit of a bear. Do you have recommendations for how it might naturally be split?
@adamsitnikadamsitnikApr 8, 2020

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I think that the two if blocks could become separate tests: value.Length == 0, s.Length == 0

 [Theory]
 [InlineData("foo", 2)]
 [InlineData("hello", 4)]
 [InlineData("foo", 3)]
 [InlineData("hello", 5)]
 [InlineData("", 0)]
 public static void LastIndexOf_EmptyString(string s, int expected)
 {
Expand DownExpand Up@@ -4325,13 +4327,13 @@ public static void LastIndexOfSequenceZeroLengthValue_Char()
 string s1 = "0172377457778667789";
 string s2 = string.Empty;
 int index = s1.LastIndexOf(s2);
 Assert.Equal(s1.Length - 1, index);
 Assert.Equal(s1.Length, index);

 // A zero-length value is always "found" at the start of the span.
 // A zero-length value is always "found" at the end of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
 Assert.Equal(0, index);
 Assert.Equal(span.Length, index);
 }

 [Fact]
Expand All@@ -4356,7 +4358,6 @@ public static void LastIndexOfSequenceLengthOneValue_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(2, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4371,7 +4372,6 @@ public static void LastIndexOfSequenceLengthOneValueAtVeryEnd_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(5, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4386,7 +4386,6 @@ public static void LastIndexOfSequenceLengthOneValueMultipleTimes_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(5, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4401,7 +4400,6 @@ public static void LastIndexOfSequenceLengthOneValueJustPasttVeryEnd_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(-1, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand Down

47 changes: 30 additions & 17 deletions
src/libraries/System.Globalization/tests/CompareInfo/CompareInfoTests.LastIndexOf.cs

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -17,7 +17,7 @@ public class CompareInfoLastIndexOfTests
 public static IEnumerable<object[]> LastIndexOf_TestData()
 {
 // Empty strings
 yield return new object[] { s_invariantCompare, "foo", "", 2, 3, CompareOptions.None, 2 };
 yield return new object[] { s_invariantCompare, "foo", "", 2, 3, CompareOptions.None, 3 };
 yield return new object[] { s_invariantCompare, "", "", 0, 0, CompareOptions.None, 0 };
 yield return new object[] { s_invariantCompare, "", "a", 0, 0, CompareOptions.None, -1 };
 yield return new object[] { s_invariantCompare, "", "", -1, 0, CompareOptions.None, 0 };
Expand All@@ -30,8 +30,8 @@ public static IEnumerable<object[]> LastIndexOf_TestData()
 yield return new object[] { s_invariantCompare, "Hello", "b", 5, 5, CompareOptions.None, -1 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 5, 0, CompareOptions.None, -1 };

 yield return new object[] { s_invariantCompare, "Hello", "", 5, 5, CompareOptions.None, 4 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 0, CompareOptions.None, 4 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 5, CompareOptions.None, 5 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 0, CompareOptions.None, 5 };

 // OrdinalIgnoreCase
 yield return new object[] { s_invariantCompare, "Hello", "l", 4, 5, CompareOptions.OrdinalIgnoreCase, 3 };
Expand DownExpand Up@@ -157,6 +157,32 @@ public void LastIndexOf_String(CompareInfo compareInfo, string source, string va
 // Use LastIndexOf(string, string, int, int, CompareOptions)
 Assert.Equal(expected, compareInfo.LastIndexOf(source, value, startIndex, count, options));

 // Fixup offsets so that we can call the span-based APIs.

 ReadOnlySpan<char> sourceSpan;
 int adjustmentFactor; // number of chars to add to retured index from span-based APIs

 if (startIndex == source.Length - 1 && count == source.Length)
 {
 // This idiom means "read the whole span"
 sourceSpan = source;
 adjustmentFactor = 0;
 }
 else if (startIndex == source.Length)
 {
 // Account for possible off-by-one at the call site
 sourceSpan = source.AsSpan()[^(Math.Max(0, count - 1))..];
 adjustmentFactor = source.Length - sourceSpan.Length;
 }
 else
 {
 // Bump 'startIndex' by 1, then go back 'count' chars
 sourceSpan = source.AsSpan()[..(startIndex + 1)][^count..];
 adjustmentFactor = startIndex + 1 - count;
 }

 if (expected < 0) { adjustmentFactor = 0; } // don't modify "not found" (-1) return values

 if ((compareInfo == s_invariantCompare) && ((options == CompareOptions.None) || (options == CompareOptions.IgnoreCase)))
 {
 StringComparison stringComparison = (options == CompareOptions.IgnoreCase) ? StringComparison.InvariantCultureIgnoreCase : StringComparison.InvariantCulture;
Expand All@@ -165,20 +191,7 @@ public void LastIndexOf_String(CompareInfo compareInfo, string source, string va
 Assert.Equal(expected, source.LastIndexOf(value, startIndex, count, stringComparison));

 // Use int MemoryExtensions.LastIndexOf(this ReadOnlySpan<char>, ReadOnlySpan<char>, StringComparison)
 // Filter differences betweeen string-based and Span-based LastIndexOf
 // - Empty value handling - https://github.com/dotnet/runtime/issues/13382
 // - Negative count
 if (value.Length == 0 || count < 0)
 return;

 if (startIndex == source.Length)
 {
 startIndex--;
 if (count > 0)
 count--;
 }
 int leftStartIndex = (startIndex - count + 1);
 Assert.Equal((expected == -1) ? -1 : (expected - leftStartIndex), source.AsSpan(leftStartIndex, count).LastIndexOf(value.AsSpan(), stringComparison));
 Assert.Equal(expected - adjustmentFactor, sourceSpan.LastIndexOf(value.AsSpan(), stringComparison));
 }
 }

Expand Down

27 changes: 17 additions & 10 deletions
src/libraries/System.Globalization/tests/CompareInfo/CompareInfoTests.cs

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -310,7 +310,7 @@ public static IEnumerable<object[]> SortKey_TestData()

 public static IEnumerable<object[]> IndexOf_TestData()
 {
 yield return new object[] { s_invariantCompare, "foo", "", 0, 0, 0 };
 yield return new object[] { s_invariantCompare, "foo", "", 0, 0, 1 };
 yield return new object[] { s_invariantCompare, "", "", 0, 0, 0 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 0, 2, -1 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 3, 3, 3 };
Expand All@@ -321,10 +321,14 @@ public static IEnumerable<object[]> IndexOf_TestData()

 public static IEnumerable<object[]> IsSortable_TestData()
 {
 yield return new object[] { "", false, false };
 yield return new object[] { "abcdefg", false, true };
 yield return new object[] { "\uD800\uDC00", true, true };
 yield return new object[] { "\uD800\uD800", true, false };
 yield return new object[] { "", false };
 yield return new object[] { "abcdefg", true };
 yield return new object[] { "\uD800\uDC00", true };

 // VS test runner for xunit doesn't handle ill-formed UTF-16 strings properly.
 // We'll send this one through as an array to avoid U+FFFD substitution.

 yield return new object[] { new char[] { '\uD800', '\uD800' }, false };
 }

 [Theory]
Expand DownExpand Up@@ -413,27 +417,30 @@ public void SortKeyMiscTest()
 public void IndexOfTest(CompareInfo compareInfo, string source, string value, int startIndex, int indexOfExpected, int lastIndexOfExpected)
 {
 Assert.Equal(indexOfExpected, compareInfo.IndexOf(source, value, startIndex));
 if (value.Length > 0)
 if (value.Length == 1)
 {
 Assert.Equal(indexOfExpected, compareInfo.IndexOf(source, value[0], startIndex));
 }

 Assert.Equal(lastIndexOfExpected, compareInfo.LastIndexOf(source, value, startIndex));
 if (value.Length > 0)
 if (value.Length == 1)
 {
 Assert.Equal(lastIndexOfExpected, compareInfo.LastIndexOf(source, value[0], startIndex));
 }
 }

 [Theory]
 [MemberData(nameof(IsSortable_TestData))]
 public void IsSortableTest(string source, bool hasSurrogate, bool expected)
 public void IsSortableTest(object sourceObj, bool expected)
 {
 string source = sourceObj as string ?? new string((char[])sourceObj);
 Assert.Equal(expected, CompareInfo.IsSortable(source));

 bool charExpectedResults = hasSurrogate ? false : expected;
 // If the string as a whole is sortable, then all chars which aren't standalone
 // surrogate halves must also be sortable.

 foreach (char c in source)
 Assert.Equal(charExpectedResults, CompareInfo.IsSortable(c));
 Assert.Equal(expected && !char.IsSurrogate(c), CompareInfo.IsSortable(c));
 }

 [Fact]
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Strip utm_, fbclid, gclid, etc. from all links on page
(function() {
var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',
'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',
'ref', 'ref_src', 'source', 'medium', 'campaign'];
function cleanUrl(url) {
try {
var u = new URL(url, window.location.origin);
var changed = false;
trackingParams.forEach(function(p) {
if (u.searchParams.has(p)) {
u.searchParams.delete(p);
changed = true;
}
});
return changed ? u.toString() : url;
} catch (e) {
return url;
}
}
function cleanLinks() {
document.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
cleanLinks();
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1) {
if (node.tagName === 'A') cleanLinks();
node.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '
Fix various LastIndexOf bugs when dealing with zero-length target substrings by GrabYourPitchforks · Pull Request #34616 · dotnet/runtime · GitHub
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Fix various LastIndexOf bugs when dealing with zero-length target substrings#34616

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Apr 7, 2020
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Fix various LastIndexOf bugs when dealing with zero-length target substrings
#34616
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32 changes: 15 additions & 17 deletions
src/libraries/Common/tests/Tests/System/StringTests.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -3379,7 +3379,6 @@ public static void IndexOfSequenceLengthOneValue_Char()
 Assert.Equal(2, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
Comment thread
GrabYourPitchforks marked this conversation as resolved.

 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand All@@ -3396,7 +3395,6 @@ public static void IndexOfSequenceLengthOneValueAtVeryEnd_Char()
 Assert.Equal(5, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand All@@ -3413,7 +3411,6 @@ public static void IndexOfSequenceLengthOneValueJustPasttVeryEnd_Char()
 Assert.Equal(-1, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand DownExpand Up@@ -3887,18 +3884,23 @@ public static void LastIndexOf_AllSubstrings(string s, string value, int startIn

 if (value.Length == 0)
 {
 int expectedIndex = s.Length > 0 ? s.Length - 1 : 0;
 int expectedStartIndex = startIndex == s.Length ? startIndex - 1 : startIndex;
 int expectedStartIndex = startIndex;
 if (s.Length == 0 && (startIndex == -1 || startIndex == 0))
 expectedStartIndex = (value.Length == 0) ? 0 : -1;
 Assert.Equal(expectedIndex, s.LastIndexOf(value, comparison));
 expectedStartIndex = 0; // empty string occurs at beginning of search space
 if (s.Length > 0 && startIndex < s.Length)
 expectedStartIndex = startIndex + 1; // empty string occurs just after the last char included in the search space

 Assert.Equal(s.Length, s.LastIndexOf(value, comparison));
 Assert.Equal(expectedStartIndex, s.LastIndexOf(value, startIndex, comparison));
 Assert.Equal(expectedIndex, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
 Assert.Equal(s.Length, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
 return;
 }

 if (s.Length == 0)
 {
 // unit test shouldn't have passed a weightless string to this routine
 Assert.NotEqual(value, string.Empty, StringComparer.FromComparison(comparison));

 Assert.Equal(-1, s.LastIndexOf(value, comparison));
 Assert.Equal(-1, s.LastIndexOf(value, startIndex, comparison));
 Assert.Equal(-1, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
Expand DownExpand Up@@ -4068,8 +4070,8 @@ public static void LastIndexOf_TurkishI_EnglishUSCulture()
 }
@adamsitnikadamsitnikApr 7, 2020

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not related to your changes: IMHO this test (IndexOf_AllSubstrings) is very complex and is trying to test too many test cases at the same time. It would be better to split it into few smaller tests with self-describing names
@GrabYourPitchforksGrabYourPitchforksApr 7, 2020

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Agreed, it's a bit of a bear. Do you have recommendations for how it might naturally be split?
@adamsitnikadamsitnikApr 8, 2020

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I think that the two if blocks could become separate tests: value.Length == 0, s.Length == 0

 [Theory]
 [InlineData("foo", 2)]
 [InlineData("hello", 4)]
 [InlineData("foo", 3)]
 [InlineData("hello", 5)]
 [InlineData("", 0)]
 public static void LastIndexOf_EmptyString(string s, int expected)
 {
Expand DownExpand Up@@ -4325,13 +4327,13 @@ public static void LastIndexOfSequenceZeroLengthValue_Char()
 string s1 = "0172377457778667789";
 string s2 = string.Empty;
 int index = s1.LastIndexOf(s2);
 Assert.Equal(s1.Length - 1, index);
 Assert.Equal(s1.Length, index);

 // A zero-length value is always "found" at the start of the span.
 // A zero-length value is always "found" at the end of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
 Assert.Equal(0, index);
 Assert.Equal(span.Length, index);
 }

 [Fact]
Expand All@@ -4356,7 +4358,6 @@ public static void LastIndexOfSequenceLengthOneValue_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(2, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4371,7 +4372,6 @@ public static void LastIndexOfSequenceLengthOneValueAtVeryEnd_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(5, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4386,7 +4386,6 @@ public static void LastIndexOfSequenceLengthOneValueMultipleTimes_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(5, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4401,7 +4400,6 @@ public static void LastIndexOfSequenceLengthOneValueJustPasttVeryEnd_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(-1, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand Down

47 changes: 30 additions & 17 deletions
src/libraries/System.Globalization/tests/CompareInfo/CompareInfoTests.LastIndexOf.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -17,7 +17,7 @@ public class CompareInfoLastIndexOfTests
 public static IEnumerable<object[]> LastIndexOf_TestData()
 {
 // Empty strings
 yield return new object[] { s_invariantCompare, "foo", "", 2, 3, CompareOptions.None, 2 };
 yield return new object[] { s_invariantCompare, "foo", "", 2, 3, CompareOptions.None, 3 };
 yield return new object[] { s_invariantCompare, "", "", 0, 0, CompareOptions.None, 0 };
 yield return new object[] { s_invariantCompare, "", "a", 0, 0, CompareOptions.None, -1 };
 yield return new object[] { s_invariantCompare, "", "", -1, 0, CompareOptions.None, 0 };
Expand All@@ -30,8 +30,8 @@ public static IEnumerable<object[]> LastIndexOf_TestData()
 yield return new object[] { s_invariantCompare, "Hello", "b", 5, 5, CompareOptions.None, -1 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 5, 0, CompareOptions.None, -1 };

 yield return new object[] { s_invariantCompare, "Hello", "", 5, 5, CompareOptions.None, 4 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 0, CompareOptions.None, 4 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 5, CompareOptions.None, 5 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 0, CompareOptions.None, 5 };

 // OrdinalIgnoreCase
 yield return new object[] { s_invariantCompare, "Hello", "l", 4, 5, CompareOptions.OrdinalIgnoreCase, 3 };
Expand DownExpand Up@@ -157,6 +157,32 @@ public void LastIndexOf_String(CompareInfo compareInfo, string source, string va
 // Use LastIndexOf(string, string, int, int, CompareOptions)
 Assert.Equal(expected, compareInfo.LastIndexOf(source, value, startIndex, count, options));

 // Fixup offsets so that we can call the span-based APIs.

 ReadOnlySpan<char> sourceSpan;
 int adjustmentFactor; // number of chars to add to retured index from span-based APIs

 if (startIndex == source.Length - 1 && count == source.Length)
 {
 // This idiom means "read the whole span"
 sourceSpan = source;
 adjustmentFactor = 0;
 }
 else if (startIndex == source.Length)
 {
 // Account for possible off-by-one at the call site
 sourceSpan = source.AsSpan()[^(Math.Max(0, count - 1))..];
 adjustmentFactor = source.Length - sourceSpan.Length;
 }
 else
 {
 // Bump 'startIndex' by 1, then go back 'count' chars
 sourceSpan = source.AsSpan()[..(startIndex + 1)][^count..];
 adjustmentFactor = startIndex + 1 - count;
 }

 if (expected < 0) { adjustmentFactor = 0; } // don't modify "not found" (-1) return values

 if ((compareInfo == s_invariantCompare) && ((options == CompareOptions.None) || (options == CompareOptions.IgnoreCase)))
 {
 StringComparison stringComparison = (options == CompareOptions.IgnoreCase) ? StringComparison.InvariantCultureIgnoreCase : StringComparison.InvariantCulture;
Expand All@@ -165,20 +191,7 @@ public void LastIndexOf_String(CompareInfo compareInfo, string source, string va
 Assert.Equal(expected, source.LastIndexOf(value, startIndex, count, stringComparison));

 // Use int MemoryExtensions.LastIndexOf(this ReadOnlySpan<char>, ReadOnlySpan<char>, StringComparison)
 // Filter differences betweeen string-based and Span-based LastIndexOf
 // - Empty value handling - https://github.com/dotnet/runtime/issues/13382
 // - Negative count
 if (value.Length == 0 || count < 0)
 return;

 if (startIndex == source.Length)
 {
 startIndex--;
 if (count > 0)
 count--;
 }
 int leftStartIndex = (startIndex - count + 1);
 Assert.Equal((expected == -1) ? -1 : (expected - leftStartIndex), source.AsSpan(leftStartIndex, count).LastIndexOf(value.AsSpan(), stringComparison));
 Assert.Equal(expected - adjustmentFactor, sourceSpan.LastIndexOf(value.AsSpan(), stringComparison));
 }
 }

Expand Down

27 changes: 17 additions & 10 deletions
src/libraries/System.Globalization/tests/CompareInfo/CompareInfoTests.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -310,7 +310,7 @@ public static IEnumerable<object[]> SortKey_TestData()

 public static IEnumerable<object[]> IndexOf_TestData()
 {
 yield return new object[] { s_invariantCompare, "foo", "", 0, 0, 0 };
 yield return new object[] { s_invariantCompare, "foo", "", 0, 0, 1 };
 yield return new object[] { s_invariantCompare, "", "", 0, 0, 0 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 0, 2, -1 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 3, 3, 3 };
Expand All@@ -321,10 +321,14 @@ public static IEnumerable<object[]> IndexOf_TestData()

 public static IEnumerable<object[]> IsSortable_TestData()
 {
 yield return new object[] { "", false, false };
 yield return new object[] { "abcdefg", false, true };
 yield return new object[] { "\uD800\uDC00", true, true };
 yield return new object[] { "\uD800\uD800", true, false };
 yield return new object[] { "", false };
 yield return new object[] { "abcdefg", true };
 yield return new object[] { "\uD800\uDC00", true };

 // VS test runner for xunit doesn't handle ill-formed UTF-16 strings properly.
 // We'll send this one through as an array to avoid U+FFFD substitution.

 yield return new object[] { new char[] { '\uD800', '\uD800' }, false };
 }

 [Theory]
Expand DownExpand Up@@ -413,27 +417,30 @@ public void SortKeyMiscTest()
 public void IndexOfTest(CompareInfo compareInfo, string source, string value, int startIndex, int indexOfExpected, int lastIndexOfExpected)
 {
 Assert.Equal(indexOfExpected, compareInfo.IndexOf(source, value, startIndex));
 if (value.Length > 0)
 if (value.Length == 1)
 {
 Assert.Equal(indexOfExpected, compareInfo.IndexOf(source, value[0], startIndex));
 }

 Assert.Equal(lastIndexOfExpected, compareInfo.LastIndexOf(source, value, startIndex));
 if (value.Length > 0)
 if (value.Length == 1)
 {
 Assert.Equal(lastIndexOfExpected, compareInfo.LastIndexOf(source, value[0], startIndex));
 }
 }

 [Theory]
 [MemberData(nameof(IsSortable_TestData))]
 public void IsSortableTest(string source, bool hasSurrogate, bool expected)
 public void IsSortableTest(object sourceObj, bool expected)
 {
 string source = sourceObj as string ?? new string((char[])sourceObj);
 Assert.Equal(expected, CompareInfo.IsSortable(source));

 bool charExpectedResults = hasSurrogate ? false : expected;
 // If the string as a whole is sortable, then all chars which aren't standalone
 // surrogate halves must also be sortable.

 foreach (char c in source)
 Assert.Equal(charExpectedResults, CompareInfo.IsSortable(c));
 Assert.Equal(expected && !char.IsSurrogate(c), CompareInfo.IsSortable(c));
 }

 [Fact]
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Auto-enable theater mode on YouTube
(function() {
function tryTheater() {
var btn = document.querySelector('button[aria-label="Theater mode"], ytd-player #player button[title="Theater mode"]');
if (btn && !btn.classList.contains('activated')) {
btn.click();
}
}
// Try immediately
tryTheater();
// Try after navigation (SPA)
var lastUrl = location.href;
setInterval(function() {
if (location.href !== lastUrl) {
lastUrl = location.href;
setTimeout(tryTheater, 500);
}
}, 1000);
// Also try on player load
var observer = new MutationObserver(tryTheater);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Fix various LastIndexOf bugs when dealing with zero-length target substrings by GrabYourPitchforks · Pull Request #34616 · dotnet/runtime · GitHub
Skip to content
Fix various LastIndexOf bugs when dealing with zero-length target substrings#34616

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privacy statement. We’ll occasionally send you account related emails.

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 Merged

GrabYourPitchforks
merged 1 commit into

from

Apr 7, 2020
 Merged


Fix various LastIndexOf bugs when dealing with zero-length target substrings
#34616
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32 changes: 15 additions & 17 deletions
src/libraries/Common/tests/Tests/System/StringTests.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -3379,7 +3379,6 @@ public static void IndexOfSequenceLengthOneValue_Char()
 Assert.Equal(2, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
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 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand All@@ -3396,7 +3395,6 @@ public static void IndexOfSequenceLengthOneValueAtVeryEnd_Char()
 Assert.Equal(5, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand All@@ -3413,7 +3411,6 @@ public static void IndexOfSequenceLengthOneValueJustPasttVeryEnd_Char()
 Assert.Equal(-1, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand DownExpand Up@@ -3887,18 +3884,23 @@ public static void LastIndexOf_AllSubstrings(string s, string value, int startIn

 if (value.Length == 0)
 {
 int expectedIndex = s.Length > 0 ? s.Length - 1 : 0;
 int expectedStartIndex = startIndex == s.Length ? startIndex - 1 : startIndex;
 int expectedStartIndex = startIndex;
 if (s.Length == 0 && (startIndex == -1 || startIndex == 0))
 expectedStartIndex = (value.Length == 0) ? 0 : -1;
 Assert.Equal(expectedIndex, s.LastIndexOf(value, comparison));
 expectedStartIndex = 0; // empty string occurs at beginning of search space
 if (s.Length > 0 && startIndex < s.Length)
 expectedStartIndex = startIndex + 1; // empty string occurs just after the last char included in the search space

 Assert.Equal(s.Length, s.LastIndexOf(value, comparison));
 Assert.Equal(expectedStartIndex, s.LastIndexOf(value, startIndex, comparison));
 Assert.Equal(expectedIndex, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
 Assert.Equal(s.Length, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
 return;
 }

 if (s.Length == 0)
 {
 // unit test shouldn't have passed a weightless string to this routine
 Assert.NotEqual(value, string.Empty, StringComparer.FromComparison(comparison));

 Assert.Equal(-1, s.LastIndexOf(value, comparison));
 Assert.Equal(-1, s.LastIndexOf(value, startIndex, comparison));
 Assert.Equal(-1, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
Expand DownExpand Up@@ -4068,8 +4070,8 @@ public static void LastIndexOf_TurkishI_EnglishUSCulture()
 }
@adamsitnikadamsitnikApr 7, 2020

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not related to your changes: IMHO this test (IndexOf_AllSubstrings) is very complex and is trying to test too many test cases at the same time. It would be better to split it into few smaller tests with self-describing names
@GrabYourPitchforksGrabYourPitchforksApr 7, 2020

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Agreed, it's a bit of a bear. Do you have recommendations for how it might naturally be split?
@adamsitnikadamsitnikApr 8, 2020

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I think that the two if blocks could become separate tests: value.Length == 0, s.Length == 0

 [Theory]
 [InlineData("foo", 2)]
 [InlineData("hello", 4)]
 [InlineData("foo", 3)]
 [InlineData("hello", 5)]
 [InlineData("", 0)]
 public static void LastIndexOf_EmptyString(string s, int expected)
 {
Expand DownExpand Up@@ -4325,13 +4327,13 @@ public static void LastIndexOfSequenceZeroLengthValue_Char()
 string s1 = "0172377457778667789";
 string s2 = string.Empty;
 int index = s1.LastIndexOf(s2);
 Assert.Equal(s1.Length - 1, index);
 Assert.Equal(s1.Length, index);

 // A zero-length value is always "found" at the start of the span.
 // A zero-length value is always "found" at the end of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
 Assert.Equal(0, index);
 Assert.Equal(span.Length, index);
 }

 [Fact]
Expand All@@ -4356,7 +4358,6 @@ public static void LastIndexOfSequenceLengthOneValue_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(2, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4371,7 +4372,6 @@ public static void LastIndexOfSequenceLengthOneValueAtVeryEnd_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(5, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4386,7 +4386,6 @@ public static void LastIndexOfSequenceLengthOneValueMultipleTimes_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(5, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4401,7 +4400,6 @@ public static void LastIndexOfSequenceLengthOneValueJustPasttVeryEnd_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(-1, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand Down

47 changes: 30 additions & 17 deletions
src/libraries/System.Globalization/tests/CompareInfo/CompareInfoTests.LastIndexOf.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -17,7 +17,7 @@ public class CompareInfoLastIndexOfTests
 public static IEnumerable<object[]> LastIndexOf_TestData()
 {
 // Empty strings
 yield return new object[] { s_invariantCompare, "foo", "", 2, 3, CompareOptions.None, 2 };
 yield return new object[] { s_invariantCompare, "foo", "", 2, 3, CompareOptions.None, 3 };
 yield return new object[] { s_invariantCompare, "", "", 0, 0, CompareOptions.None, 0 };
 yield return new object[] { s_invariantCompare, "", "a", 0, 0, CompareOptions.None, -1 };
 yield return new object[] { s_invariantCompare, "", "", -1, 0, CompareOptions.None, 0 };
Expand All@@ -30,8 +30,8 @@ public static IEnumerable<object[]> LastIndexOf_TestData()
 yield return new object[] { s_invariantCompare, "Hello", "b", 5, 5, CompareOptions.None, -1 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 5, 0, CompareOptions.None, -1 };

 yield return new object[] { s_invariantCompare, "Hello", "", 5, 5, CompareOptions.None, 4 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 0, CompareOptions.None, 4 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 5, CompareOptions.None, 5 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 0, CompareOptions.None, 5 };

 // OrdinalIgnoreCase
 yield return new object[] { s_invariantCompare, "Hello", "l", 4, 5, CompareOptions.OrdinalIgnoreCase, 3 };
Expand DownExpand Up@@ -157,6 +157,32 @@ public void LastIndexOf_String(CompareInfo compareInfo, string source, string va
 // Use LastIndexOf(string, string, int, int, CompareOptions)
 Assert.Equal(expected, compareInfo.LastIndexOf(source, value, startIndex, count, options));

 // Fixup offsets so that we can call the span-based APIs.

 ReadOnlySpan<char> sourceSpan;
 int adjustmentFactor; // number of chars to add to retured index from span-based APIs

 if (startIndex == source.Length - 1 && count == source.Length)
 {
 // This idiom means "read the whole span"
 sourceSpan = source;
 adjustmentFactor = 0;
 }
 else if (startIndex == source.Length)
 {
 // Account for possible off-by-one at the call site
 sourceSpan = source.AsSpan()[^(Math.Max(0, count - 1))..];
 adjustmentFactor = source.Length - sourceSpan.Length;
 }
 else
 {
 // Bump 'startIndex' by 1, then go back 'count' chars
 sourceSpan = source.AsSpan()[..(startIndex + 1)][^count..];
 adjustmentFactor = startIndex + 1 - count;
 }

 if (expected < 0) { adjustmentFactor = 0; } // don't modify "not found" (-1) return values

 if ((compareInfo == s_invariantCompare) && ((options == CompareOptions.None) || (options == CompareOptions.IgnoreCase)))
 {
 StringComparison stringComparison = (options == CompareOptions.IgnoreCase) ? StringComparison.InvariantCultureIgnoreCase : StringComparison.InvariantCulture;
Expand All@@ -165,20 +191,7 @@ public void LastIndexOf_String(CompareInfo compareInfo, string source, string va
 Assert.Equal(expected, source.LastIndexOf(value, startIndex, count, stringComparison));

 // Use int MemoryExtensions.LastIndexOf(this ReadOnlySpan<char>, ReadOnlySpan<char>, StringComparison)
 // Filter differences betweeen string-based and Span-based LastIndexOf
 // - Empty value handling - https://github.com/dotnet/runtime/issues/13382
 // - Negative count
 if (value.Length == 0 || count < 0)
 return;

 if (startIndex == source.Length)
 {
 startIndex--;
 if (count > 0)
 count--;
 }
 int leftStartIndex = (startIndex - count + 1);
 Assert.Equal((expected == -1) ? -1 : (expected - leftStartIndex), source.AsSpan(leftStartIndex, count).LastIndexOf(value.AsSpan(), stringComparison));
 Assert.Equal(expected - adjustmentFactor, sourceSpan.LastIndexOf(value.AsSpan(), stringComparison));
 }
 }

Expand Down

27 changes: 17 additions & 10 deletions
src/libraries/System.Globalization/tests/CompareInfo/CompareInfoTests.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -310,7 +310,7 @@ public static IEnumerable<object[]> SortKey_TestData()

 public static IEnumerable<object[]> IndexOf_TestData()
 {
 yield return new object[] { s_invariantCompare, "foo", "", 0, 0, 0 };
 yield return new object[] { s_invariantCompare, "foo", "", 0, 0, 1 };
 yield return new object[] { s_invariantCompare, "", "", 0, 0, 0 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 0, 2, -1 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 3, 3, 3 };
Expand All@@ -321,10 +321,14 @@ public static IEnumerable<object[]> IndexOf_TestData()

 public static IEnumerable<object[]> IsSortable_TestData()
 {
 yield return new object[] { "", false, false };
 yield return new object[] { "abcdefg", false, true };
 yield return new object[] { "\uD800\uDC00", true, true };
 yield return new object[] { "\uD800\uD800", true, false };
 yield return new object[] { "", false };
 yield return new object[] { "abcdefg", true };
 yield return new object[] { "\uD800\uDC00", true };

 // VS test runner for xunit doesn't handle ill-formed UTF-16 strings properly.
 // We'll send this one through as an array to avoid U+FFFD substitution.

 yield return new object[] { new char[] { '\uD800', '\uD800' }, false };
 }

 [Theory]
Expand DownExpand Up@@ -413,27 +417,30 @@ public void SortKeyMiscTest()
 public void IndexOfTest(CompareInfo compareInfo, string source, string value, int startIndex, int indexOfExpected, int lastIndexOfExpected)
 {
 Assert.Equal(indexOfExpected, compareInfo.IndexOf(source, value, startIndex));
 if (value.Length > 0)
 if (value.Length == 1)
 {
 Assert.Equal(indexOfExpected, compareInfo.IndexOf(source, value[0], startIndex));
 }

 Assert.Equal(lastIndexOfExpected, compareInfo.LastIndexOf(source, value, startIndex));
 if (value.Length > 0)
 if (value.Length == 1)
 {
 Assert.Equal(lastIndexOfExpected, compareInfo.LastIndexOf(source, value[0], startIndex));
 }
 }

 [Theory]
 [MemberData(nameof(IsSortable_TestData))]
 public void IsSortableTest(string source, bool hasSurrogate, bool expected)
 public void IsSortableTest(object sourceObj, bool expected)
 {
 string source = sourceObj as string ?? new string((char[])sourceObj);
 Assert.Equal(expected, CompareInfo.IsSortable(source));

 bool charExpectedResults = hasSurrogate ? false : expected;
 // If the string as a whole is sortable, then all chars which aren't standalone
 // surrogate halves must also be sortable.

 foreach (char c in source)
 Assert.Equal(charExpectedResults, CompareInfo.IsSortable(c));
 Assert.Equal(expected && !char.IsSurrogate(c), CompareInfo.IsSortable(c));
 }

 [Fact]
Expand Down
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if (__m === '*' || __re.test(location.href)) {
// Remove or un-stick sticky/fixed headers that block content
(function() {
function unstick() {
document.querySelectorAll('header, nav, [role="banner"], .header, .navbar, .sticky, .fixed-top, [style*="position: fixed"], [style*="position:sticky"]').forEach(function(el) {
if (el.style.position === 'fixed' || el.style.position === 'sticky' || getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {
el.style.position = 'static';
el.style.top = 'auto';
el.style.zIndex = 'auto';
}
});
}
unstick();
var observer = new MutationObserver(unstick);
observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });
})();
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
})();
Fix various LastIndexOf bugs when dealing with zero-length target substrings by GrabYourPitchforks · Pull Request #34616 · dotnet/runtime · GitHub
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Apr 7, 2020
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Fix various LastIndexOf bugs when dealing with zero-length target substrings
#34616
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32 changes: 15 additions & 17 deletions
src/libraries/Common/tests/Tests/System/StringTests.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -3379,7 +3379,6 @@ public static void IndexOfSequenceLengthOneValue_Char()
 Assert.Equal(2, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
Comment thread
GrabYourPitchforks marked this conversation as resolved.

 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand All@@ -3396,7 +3395,6 @@ public static void IndexOfSequenceLengthOneValueAtVeryEnd_Char()
 Assert.Equal(5, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand All@@ -3413,7 +3411,6 @@ public static void IndexOfSequenceLengthOneValueJustPasttVeryEnd_Char()
 Assert.Equal(-1, index);
 Assert.Equal(index, s1.IndexOf(s2, StringComparison.Ordinal));

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.IndexOf(value);
Expand DownExpand Up@@ -3887,18 +3884,23 @@ public static void LastIndexOf_AllSubstrings(string s, string value, int startIn

 if (value.Length == 0)
 {
 int expectedIndex = s.Length > 0 ? s.Length - 1 : 0;
 int expectedStartIndex = startIndex == s.Length ? startIndex - 1 : startIndex;
 int expectedStartIndex = startIndex;
 if (s.Length == 0 && (startIndex == -1 || startIndex == 0))
 expectedStartIndex = (value.Length == 0) ? 0 : -1;
 Assert.Equal(expectedIndex, s.LastIndexOf(value, comparison));
 expectedStartIndex = 0; // empty string occurs at beginning of search space
 if (s.Length > 0 && startIndex < s.Length)
 expectedStartIndex = startIndex + 1; // empty string occurs just after the last char included in the search space

 Assert.Equal(s.Length, s.LastIndexOf(value, comparison));
 Assert.Equal(expectedStartIndex, s.LastIndexOf(value, startIndex, comparison));
 Assert.Equal(expectedIndex, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
 Assert.Equal(s.Length, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
 return;
 }

 if (s.Length == 0)
 {
 // unit test shouldn't have passed a weightless string to this routine
 Assert.NotEqual(value, string.Empty, StringComparer.FromComparison(comparison));

 Assert.Equal(-1, s.LastIndexOf(value, comparison));
 Assert.Equal(-1, s.LastIndexOf(value, startIndex, comparison));
 Assert.Equal(-1, s.AsSpan().LastIndexOf(value.AsSpan(), comparison));
Expand DownExpand Up@@ -4068,8 +4070,8 @@ public static void LastIndexOf_TurkishI_EnglishUSCulture()
 }
@adamsitnikadamsitnikApr 7, 2020

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not related to your changes: IMHO this test (IndexOf_AllSubstrings) is very complex and is trying to test too many test cases at the same time. It would be better to split it into few smaller tests with self-describing names
@GrabYourPitchforksGrabYourPitchforksApr 7, 2020

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Agreed, it's a bit of a bear. Do you have recommendations for how it might naturally be split?
@adamsitnikadamsitnikApr 8, 2020

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I think that the two if blocks could become separate tests: value.Length == 0, s.Length == 0

 [Theory]
 [InlineData("foo", 2)]
 [InlineData("hello", 4)]
 [InlineData("foo", 3)]
 [InlineData("hello", 5)]
 [InlineData("", 0)]
 public static void LastIndexOf_EmptyString(string s, int expected)
 {
Expand DownExpand Up@@ -4325,13 +4327,13 @@ public static void LastIndexOfSequenceZeroLengthValue_Char()
 string s1 = "0172377457778667789";
 string s2 = string.Empty;
 int index = s1.LastIndexOf(s2);
 Assert.Equal(s1.Length - 1, index);
 Assert.Equal(s1.Length, index);

 // A zero-length value is always "found" at the start of the span.
 // A zero-length value is always "found" at the end of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
 Assert.Equal(0, index);
 Assert.Equal(span.Length, index);
 }

 [Fact]
Expand All@@ -4356,7 +4358,6 @@ public static void LastIndexOfSequenceLengthOneValue_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(2, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4371,7 +4372,6 @@ public static void LastIndexOfSequenceLengthOneValueAtVeryEnd_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(5, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4386,7 +4386,6 @@ public static void LastIndexOfSequenceLengthOneValueMultipleTimes_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(5, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand All@@ -4401,7 +4400,6 @@ public static void LastIndexOfSequenceLengthOneValueJustPasttVeryEnd_Char()
 int index = s1.LastIndexOf(s2);
 Assert.Equal(-1, index);

 // A zero-length value is always "found" at the start of the span.
 ReadOnlySpan<char> span = s1.AsSpan();
 ReadOnlySpan<char> value = s2.AsSpan();
 index = span.LastIndexOf(value);
Expand Down

47 changes: 30 additions & 17 deletions
src/libraries/System.Globalization/tests/CompareInfo/CompareInfoTests.LastIndexOf.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -17,7 +17,7 @@ public class CompareInfoLastIndexOfTests
 public static IEnumerable<object[]> LastIndexOf_TestData()
 {
 // Empty strings
 yield return new object[] { s_invariantCompare, "foo", "", 2, 3, CompareOptions.None, 2 };
 yield return new object[] { s_invariantCompare, "foo", "", 2, 3, CompareOptions.None, 3 };
 yield return new object[] { s_invariantCompare, "", "", 0, 0, CompareOptions.None, 0 };
 yield return new object[] { s_invariantCompare, "", "a", 0, 0, CompareOptions.None, -1 };
 yield return new object[] { s_invariantCompare, "", "", -1, 0, CompareOptions.None, 0 };
Expand All@@ -30,8 +30,8 @@ public static IEnumerable<object[]> LastIndexOf_TestData()
 yield return new object[] { s_invariantCompare, "Hello", "b", 5, 5, CompareOptions.None, -1 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 5, 0, CompareOptions.None, -1 };

 yield return new object[] { s_invariantCompare, "Hello", "", 5, 5, CompareOptions.None, 4 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 0, CompareOptions.None, 4 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 5, CompareOptions.None, 5 };
 yield return new object[] { s_invariantCompare, "Hello", "", 5, 0, CompareOptions.None, 5 };

 // OrdinalIgnoreCase
 yield return new object[] { s_invariantCompare, "Hello", "l", 4, 5, CompareOptions.OrdinalIgnoreCase, 3 };
Expand DownExpand Up@@ -157,6 +157,32 @@ public void LastIndexOf_String(CompareInfo compareInfo, string source, string va
 // Use LastIndexOf(string, string, int, int, CompareOptions)
 Assert.Equal(expected, compareInfo.LastIndexOf(source, value, startIndex, count, options));

 // Fixup offsets so that we can call the span-based APIs.

 ReadOnlySpan<char> sourceSpan;
 int adjustmentFactor; // number of chars to add to retured index from span-based APIs

 if (startIndex == source.Length - 1 && count == source.Length)
 {
 // This idiom means "read the whole span"
 sourceSpan = source;
 adjustmentFactor = 0;
 }
 else if (startIndex == source.Length)
 {
 // Account for possible off-by-one at the call site
 sourceSpan = source.AsSpan()[^(Math.Max(0, count - 1))..];
 adjustmentFactor = source.Length - sourceSpan.Length;
 }
 else
 {
 // Bump 'startIndex' by 1, then go back 'count' chars
 sourceSpan = source.AsSpan()[..(startIndex + 1)][^count..];
 adjustmentFactor = startIndex + 1 - count;
 }

 if (expected < 0) { adjustmentFactor = 0; } // don't modify "not found" (-1) return values

 if ((compareInfo == s_invariantCompare) && ((options == CompareOptions.None) || (options == CompareOptions.IgnoreCase)))
 {
 StringComparison stringComparison = (options == CompareOptions.IgnoreCase) ? StringComparison.InvariantCultureIgnoreCase : StringComparison.InvariantCulture;
Expand All@@ -165,20 +191,7 @@ public void LastIndexOf_String(CompareInfo compareInfo, string source, string va
 Assert.Equal(expected, source.LastIndexOf(value, startIndex, count, stringComparison));

 // Use int MemoryExtensions.LastIndexOf(this ReadOnlySpan<char>, ReadOnlySpan<char>, StringComparison)
 // Filter differences betweeen string-based and Span-based LastIndexOf
 // - Empty value handling - https://github.com/dotnet/runtime/issues/13382
 // - Negative count
 if (value.Length == 0 || count < 0)
 return;

 if (startIndex == source.Length)
 {
 startIndex--;
 if (count > 0)
 count--;
 }
 int leftStartIndex = (startIndex - count + 1);
 Assert.Equal((expected == -1) ? -1 : (expected - leftStartIndex), source.AsSpan(leftStartIndex, count).LastIndexOf(value.AsSpan(), stringComparison));
 Assert.Equal(expected - adjustmentFactor, sourceSpan.LastIndexOf(value.AsSpan(), stringComparison));
 }
 }

Expand Down

27 changes: 17 additions & 10 deletions
src/libraries/System.Globalization/tests/CompareInfo/CompareInfoTests.cs

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -310,7 +310,7 @@ public static IEnumerable<object[]> SortKey_TestData()

 public static IEnumerable<object[]> IndexOf_TestData()
 {
 yield return new object[] { s_invariantCompare, "foo", "", 0, 0, 0 };
 yield return new object[] { s_invariantCompare, "foo", "", 0, 0, 1 };
 yield return new object[] { s_invariantCompare, "", "", 0, 0, 0 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 0, 2, -1 };
 yield return new object[] { s_invariantCompare, "Hello", "l", 3, 3, 3 };
Expand All@@ -321,10 +321,14 @@ public static IEnumerable<object[]> IndexOf_TestData()

 public static IEnumerable<object[]> IsSortable_TestData()
 {
 yield return new object[] { "", false, false };
 yield return new object[] { "abcdefg", false, true };
 yield return new object[] { "\uD800\uDC00", true, true };
 yield return new object[] { "\uD800\uD800", true, false };
 yield return new object[] { "", false };
 yield return new object[] { "abcdefg", true };
 yield return new object[] { "\uD800\uDC00", true };

 // VS test runner for xunit doesn't handle ill-formed UTF-16 strings properly.
 // We'll send this one through as an array to avoid U+FFFD substitution.

 yield return new object[] { new char[] { '\uD800', '\uD800' }, false };
 }

 [Theory]
Expand DownExpand Up@@ -413,27 +417,30 @@ public void SortKeyMiscTest()
 public void IndexOfTest(CompareInfo compareInfo, string source, string value, int startIndex, int indexOfExpected, int lastIndexOfExpected)
 {
 Assert.Equal(indexOfExpected, compareInfo.IndexOf(source, value, startIndex));
 if (value.Length > 0)
 if (value.Length == 1)
 {
 Assert.Equal(indexOfExpected, compareInfo.IndexOf(source, value[0], startIndex));
 }

 Assert.Equal(lastIndexOfExpected, compareInfo.LastIndexOf(source, value, startIndex));
 if (value.Length > 0)
 if (value.Length == 1)
 {
 Assert.Equal(lastIndexOfExpected, compareInfo.LastIndexOf(source, value[0], startIndex));
 }
 }

 [Theory]
 [MemberData(nameof(IsSortable_TestData))]
 public void IsSortableTest(string source, bool hasSurrogate, bool expected)
 public void IsSortableTest(object sourceObj, bool expected)
 {
 string source = sourceObj as string ?? new string((char[])sourceObj);
 Assert.Equal(expected, CompareInfo.IsSortable(source));

 bool charExpectedResults = hasSurrogate ? false : expected;
 // If the string as a whole is sortable, then all chars which aren't standalone
 // surrogate halves must also be sortable.

 foreach (char c in source)
 Assert.Equal(charExpectedResults, CompareInfo.IsSortable(c));
 Assert.Equal(expected && !char.IsSurrogate(c), CompareInfo.IsSortable(c));
 }

 [Fact]
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