Fix IndexOf upper-bound guard in ImmutableArray/List - #124967

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Fix IndexOf upper-bound guard in ImmutableArray/List#124967
MihaZupan merged 9 commits into
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prozolic:indexof

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Change the startIndex upper-bound validation in IndexOf from '< Count' to '<= Count' for ImmutableArray<T>,
ImmutableArray<T>.Builder, and add upper-bound validation in ImmutableList<T>.Node.
This aligns the behavior with Array.IndexOf, which permits index == Count provided count is 0.

Change:

  • Change the startIndex upper-bound validation in IndexOf from '< Count' to '<= Count' for ImmutableArray,
    ImmutableArray<T>.Builder.
  • Add upper-bound validation in ImmutableList<T>.Node to match the behavior of ImmutableArray<T>.
  • Add test case and fix test case to also validate the parameter name as the fix in Use Requires.Range in LastIndexOf #124560.

Fixes#124968

@prozolic
Fix IndexOf upper-bound guard in ImmutableArray/List
a338be4
Change the startIndex upper-bound validation in IndexOf from
'< Count' to '<= Count' for ImmutableArray<T>,
ImmutableArray<T>.Builder, and add upper-bound validation
in ImmutableList<T>.Node.
This aligns the behavior with Array.IndexOf, which permits
index == Count provided count is 0.
CopilotAI review requested due to automatic review settings February 27, 2026 13:58
@dotnet-policy-servicedotnet-policy-serviceBot added the community-contribution Indicates that the PR has been added by a community member label Feb 27, 2026
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Pull request overview

This PR fixes the IndexOf upper-bound validation in ImmutableArray<T>, ImmutableArray<T>.Builder, and ImmutableList<T>.Node to align with Array.IndexOf behavior, which allows startIndex == Count when count == 0. The PR is a follow-up to #124560 which fixed similar issues in LastIndexOf.

Changes:

  • Modified upper-bound validation for startIndex/index parameter from < Count to <= Count in IndexOf methods
  • Added upper-bound validation to ImmutableList<T>.Node.IndexOf which was previously missing
  • Enhanced tests to validate parameter names in thrown exceptions and added consistency tests with Array.IndexOf

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

Show a summary per file
FileDescription
ImmutableArray_1.csChanged startIndex upper-bound validation from < Length to <= Length in IndexOf
ImmutableArray_1.Builder.csChanged startIndex upper-bound validation from < Count to <= Count in IndexOf
ImmutableList_1.Node.csAdded upper-bound check to index validation (from single >= 0 check to >= 0 && <= Count), added redundant count upper-bound validation
IndexOfTests.csAdded indexParameterName parameter to test signature, enhanced tests to validate exception parameter names and added edge case tests
ImmutableArrayTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "startIndex" parameter
ImmutableArrayBuilderTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "startIndex" parameter
ImmutableListTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "index" parameter
ImmutableListBuilderTest.csUpdated test calls to pass "index" parameter

Comment thread...raries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList_1.Node.cs Outdated
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Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

Comment threadsrc/libraries/System.Collections.Immutable/tests/IndexOfTests.cs
@prozolic
Update src/libraries/System.Collections.Immutable/tests/IndexOfTests.cs
ae3f07b
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
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@MihaZupan I've addressed your feedback. Could you please take another look when you get a chance?

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Comment threadsrc/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray_1.cs Outdated
Comment thread...raries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList_1.Node.cs Outdated
@MihaZupan
Handle index + count overflows
0a14ce3
Co-authored-by: Miha Zupan <mihazupan.zupan1@gmail.com>
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MihaZupan merged commit 56b0396 into dotnet:mainApr 19, 2026
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svick added a commit to svick/runtime that referenced this pull request Apr 20, 2026
@svick
Fix mixed CRLF/LF line endings in ImmutableArray_1.cs
0615793
PR dotnet#124967 accidentally committed two lines with CRLF endings into
a file that uses LF, causing git to perpetually report the file as
modified on Windows (core.autocrlf=true).
Renormalize to consistent LF endings.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@svicksvick mentioned this pull request Apr 20, 2026
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@svick
Fix mixed CRLF/LF line endings in ImmutableArray_1.cs (#127159)
0f1536b
PR #124967 accidentally committed two lines with CRLF endings into a
file that uses LF, causing git to perpetually report the file as
modified on Windows (core.autocrlf=true).
Renormalize to consistent LF endings.
cc: @MihaZupan
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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ImmutableArray<T>.IndexOf throws ArgumentOutOfRangeException when startIndex equals Length and count is 0

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Fix IndexOf upper-bound guard in ImmutableArray/List - #124967
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MihaZupan merged 9 commits into
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prozolic:indexof
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Fix IndexOf upper-bound guard in ImmutableArray/List#124967
MihaZupan merged 9 commits into
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prozolic:indexof
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edited by MihaZupan

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Change the startIndex upper-bound validation in IndexOf from '< Count' to '<= Count' for ImmutableArray<T>,
ImmutableArray<T>.Builder, and add upper-bound validation in ImmutableList<T>.Node.

This aligns the behavior with Array.IndexOf, which permits index == Count provided count is 0.
Change:
  • Change the startIndex upper-bound validation in IndexOf from '< Count' to '<= Count' for ImmutableArray,
    ImmutableArray<T>.Builder.
  • Add upper-bound validation in ImmutableList<T>.Node to match the behavior of ImmutableArray<T>.
  • Add test case and fix test case to also validate the parameter name as the fix in Use Requires.Range in LastIndexOf #124560.
Fixes#124968
@prozolic
Fix IndexOf upper-bound guard in ImmutableArray/List
a338be4
Change the startIndex upper-bound validation in IndexOf from
'< Count' to '<= Count' for ImmutableArray<T>,
ImmutableArray<T>.Builder, and add upper-bound validation
in ImmutableList<T>.Node.
This aligns the behavior with Array.IndexOf, which permits
index == Count provided count is 0.
CopilotAI
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Pull request overview
This PR fixes the IndexOf upper-bound validation in ImmutableArray<T>, ImmutableArray<T>.Builder, and ImmutableList<T>.Node to align with Array.IndexOf behavior, which allows startIndex == Count when count == 0. The PR is a follow-up to #124560 which fixed similar issues in LastIndexOf.
Changes:
  • Modified upper-bound validation for startIndex/index parameter from < Count to <= Count in IndexOf methods
  • Added upper-bound validation to ImmutableList<T>.Node.IndexOf which was previously missing
  • Enhanced tests to validate parameter names in thrown exceptions and added consistency tests with Array.IndexOf
Reviewed changes
Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.
Show a summary per file
FileDescription
ImmutableArray_1.csChanged startIndex upper-bound validation from < Length to <= Length in IndexOf
ImmutableArray_1.Builder.csChanged startIndex upper-bound validation from < Count to <= Count in IndexOf
ImmutableList_1.Node.csAdded upper-bound check to index validation (from single >= 0 check to >= 0 && <= Count), added redundant count upper-bound validation
IndexOfTests.csAdded indexParameterName parameter to test signature, enhanced tests to validate exception parameter names and added edge case tests
ImmutableArrayTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "startIndex" parameter
ImmutableArrayBuilderTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "startIndex" parameter
ImmutableListTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "index" parameter
ImmutableListBuilderTest.csUpdated test calls to pass "index" parameter
Comment thread...raries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList_1.Node.cs
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Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.
Comment threadsrc/libraries/System.Collections.Immutable/tests/IndexOfTests.cs
@prozolic
Update src/libraries/System.Collections.Immutable/tests/IndexOfTests.cs
ae3f07b
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
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@MihaZupan I've addressed your feedback. Could you please take another look when you get a chance?
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Comment threadsrc/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray_1.cs
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Comment thread...raries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList_1.Node.cs
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Handle index + count overflows
0a14ce3
Co-authored-by: Miha Zupan <mihazupan.zupan1@gmail.com>
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Fix mixed CRLF/LF line endings in ImmutableArray_1.cs
0615793
PR dotnet#124967 accidentally committed two lines with CRLF endings into
a file that uses LF, causing git to perpetually report the file as
modified on Windows (core.autocrlf=true).
Renormalize to consistent LF endings.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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@svick
Fix mixed CRLF/LF line endings in ImmutableArray_1.cs (#127159)
0f1536b
PR #124967 accidentally committed two lines with CRLF endings into a
file that uses LF, causing git to perpetually report the file as
modified on Windows (core.autocrlf=true).
Renormalize to consistent LF endings.
cc: @MihaZupan
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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ImmutableArray<T>.IndexOf throws ArgumentOutOfRangeException when startIndex equals Length and count is 0


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Fix IndexOf upper-bound guard in ImmutableArray/List - #124967
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Fix IndexOf upper-bound guard in ImmutableArray/List#124967
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edited by MihaZupan

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Change the startIndex upper-bound validation in IndexOf from '< Count' to '<= Count' for ImmutableArray<T>,
ImmutableArray<T>.Builder, and add upper-bound validation in ImmutableList<T>.Node.

This aligns the behavior with Array.IndexOf, which permits index == Count provided count is 0.
Change:
  • Change the startIndex upper-bound validation in IndexOf from '< Count' to '<= Count' for ImmutableArray,
    ImmutableArray<T>.Builder.
  • Add upper-bound validation in ImmutableList<T>.Node to match the behavior of ImmutableArray<T>.
  • Add test case and fix test case to also validate the parameter name as the fix in Use Requires.Range in LastIndexOf #124560.
Fixes#124968
@prozolic
Fix IndexOf upper-bound guard in ImmutableArray/List
a338be4
Change the startIndex upper-bound validation in IndexOf from
'< Count' to '<= Count' for ImmutableArray<T>,
ImmutableArray<T>.Builder, and add upper-bound validation
in ImmutableList<T>.Node.
This aligns the behavior with Array.IndexOf, which permits
index == Count provided count is 0.
CopilotAI
review requested due to automatic review settings
February 27, 2026 13:58
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Pull request overview
This PR fixes the IndexOf upper-bound validation in ImmutableArray<T>, ImmutableArray<T>.Builder, and ImmutableList<T>.Node to align with Array.IndexOf behavior, which allows startIndex == Count when count == 0. The PR is a follow-up to #124560 which fixed similar issues in LastIndexOf.
Changes:
  • Modified upper-bound validation for startIndex/index parameter from < Count to <= Count in IndexOf methods
  • Added upper-bound validation to ImmutableList<T>.Node.IndexOf which was previously missing
  • Enhanced tests to validate parameter names in thrown exceptions and added consistency tests with Array.IndexOf
Reviewed changes
Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.
Show a summary per file
FileDescription
ImmutableArray_1.csChanged startIndex upper-bound validation from < Length to <= Length in IndexOf
ImmutableArray_1.Builder.csChanged startIndex upper-bound validation from < Count to <= Count in IndexOf
ImmutableList_1.Node.csAdded upper-bound check to index validation (from single >= 0 check to >= 0 && <= Count), added redundant count upper-bound validation
IndexOfTests.csAdded indexParameterName parameter to test signature, enhanced tests to validate exception parameter names and added edge case tests
ImmutableArrayTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "startIndex" parameter
ImmutableArrayBuilderTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "startIndex" parameter
ImmutableListTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "index" parameter
ImmutableListBuilderTest.csUpdated test calls to pass "index" parameter
Comment thread...raries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList_1.Node.cs
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Comment threadsrc/libraries/System.Collections.Immutable/tests/IndexOfTests.cs
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Update src/libraries/System.Collections.Immutable/tests/IndexOfTests.cs
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Comment threadsrc/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray_1.cs
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Comment thread...raries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList_1.Node.cs
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Handle index + count overflows
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Fix mixed CRLF/LF line endings in ImmutableArray_1.cs
0615793
PR dotnet#124967 accidentally committed two lines with CRLF endings into
a file that uses LF, causing git to perpetually report the file as
modified on Windows (core.autocrlf=true).
Renormalize to consistent LF endings.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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Fix mixed CRLF/LF line endings in ImmutableArray_1.cs (#127159)
0f1536b
PR #124967 accidentally committed two lines with CRLF endings into a
file that uses LF, causing git to perpetually report the file as
modified on Windows (core.autocrlf=true).
Renormalize to consistent LF endings.
cc: @MihaZupan
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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ImmutableArray<T>.IndexOf throws ArgumentOutOfRangeException when startIndex equals Length and count is 0


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, 'i');
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try {
var __m = "*";
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Fix IndexOf upper-bound guard in ImmutableArray/List - #124967
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Fix IndexOf upper-bound guard in ImmutableArray/List#124967
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Change the startIndex upper-bound validation in IndexOf from '< Count' to '<= Count' for ImmutableArray<T>,
ImmutableArray<T>.Builder, and add upper-bound validation in ImmutableList<T>.Node.

This aligns the behavior with Array.IndexOf, which permits index == Count provided count is 0.
Change:
  • Change the startIndex upper-bound validation in IndexOf from '< Count' to '<= Count' for ImmutableArray,
    ImmutableArray<T>.Builder.
  • Add upper-bound validation in ImmutableList<T>.Node to match the behavior of ImmutableArray<T>.
  • Add test case and fix test case to also validate the parameter name as the fix in Use Requires.Range in LastIndexOf #124560.
Fixes#124968
@prozolic
Fix IndexOf upper-bound guard in ImmutableArray/List
a338be4
Change the startIndex upper-bound validation in IndexOf from
'< Count' to '<= Count' for ImmutableArray<T>,
ImmutableArray<T>.Builder, and add upper-bound validation
in ImmutableList<T>.Node.
This aligns the behavior with Array.IndexOf, which permits
index == Count provided count is 0.
CopilotAI
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Pull request overview
This PR fixes the IndexOf upper-bound validation in ImmutableArray<T>, ImmutableArray<T>.Builder, and ImmutableList<T>.Node to align with Array.IndexOf behavior, which allows startIndex == Count when count == 0. The PR is a follow-up to #124560 which fixed similar issues in LastIndexOf.
Changes:
  • Modified upper-bound validation for startIndex/index parameter from < Count to <= Count in IndexOf methods
  • Added upper-bound validation to ImmutableList<T>.Node.IndexOf which was previously missing
  • Enhanced tests to validate parameter names in thrown exceptions and added consistency tests with Array.IndexOf
Reviewed changes
Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.
Show a summary per file
FileDescription
ImmutableArray_1.csChanged startIndex upper-bound validation from < Length to <= Length in IndexOf
ImmutableArray_1.Builder.csChanged startIndex upper-bound validation from < Count to <= Count in IndexOf
ImmutableList_1.Node.csAdded upper-bound check to index validation (from single >= 0 check to >= 0 && <= Count), added redundant count upper-bound validation
IndexOfTests.csAdded indexParameterName parameter to test signature, enhanced tests to validate exception parameter names and added edge case tests
ImmutableArrayTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "startIndex" parameter
ImmutableArrayBuilderTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "startIndex" parameter
ImmutableListTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "index" parameter
ImmutableListBuilderTest.csUpdated test calls to pass "index" parameter
Comment thread...raries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList_1.Node.cs
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Pull request overview
Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.
Comment threadsrc/libraries/System.Collections.Immutable/tests/IndexOfTests.cs
@prozolic
Update src/libraries/System.Collections.Immutable/tests/IndexOfTests.cs
ae3f07b
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
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@MihaZupan I've addressed your feedback. Could you please take another look when you get a chance?
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Comment threadsrc/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray_1.cs
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Comment thread...raries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList_1.Node.cs
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Handle index + count overflows
0a14ce3
Co-authored-by: Miha Zupan <mihazupan.zupan1@gmail.com>
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Comment thread...es/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray_1.Builder.cs
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Pull request overview
Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.
@MihaZupan
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dotnet:mainApr 19, 2026

94 of 100 checks passed

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@svick
Fix mixed CRLF/LF line endings in ImmutableArray_1.cs
0615793
PR dotnet#124967 accidentally committed two lines with CRLF endings into
a file that uses LF, causing git to perpetually report the file as
modified on Windows (core.autocrlf=true).
Renormalize to consistent LF endings.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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@svick
Fix mixed CRLF/LF line endings in ImmutableArray_1.cs (#127159)
0f1536b
PR #124967 accidentally committed two lines with CRLF endings into a
file that uses LF, causing git to perpetually report the file as
modified on Windows (core.autocrlf=true).
Renormalize to consistent LF endings.
cc: @MihaZupan
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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ImmutableArray<T>.IndexOf throws ArgumentOutOfRangeException when startIndex equals Length and count is 0


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, 'i');
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injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
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})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

Skip to content
Fix IndexOf upper-bound guard in ImmutableArray/List - #124967
Merged
MihaZupan merged 9 commits into
dotnet:mainfrom 
prozolic:indexof
Apr 19, 2026
Merged
Fix IndexOf upper-bound guard in ImmutableArray/List#124967
MihaZupan merged 9 commits into
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edited by MihaZupan

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Change the startIndex upper-bound validation in IndexOf from '< Count' to '<= Count' for ImmutableArray<T>,
ImmutableArray<T>.Builder, and add upper-bound validation in ImmutableList<T>.Node.

This aligns the behavior with Array.IndexOf, which permits index == Count provided count is 0.
Change:
  • Change the startIndex upper-bound validation in IndexOf from '< Count' to '<= Count' for ImmutableArray,
    ImmutableArray<T>.Builder.
  • Add upper-bound validation in ImmutableList<T>.Node to match the behavior of ImmutableArray<T>.
  • Add test case and fix test case to also validate the parameter name as the fix in Use Requires.Range in LastIndexOf #124560.
Fixes#124968
@prozolic
Fix IndexOf upper-bound guard in ImmutableArray/List
a338be4
Change the startIndex upper-bound validation in IndexOf from
'< Count' to '<= Count' for ImmutableArray<T>,
ImmutableArray<T>.Builder, and add upper-bound validation
in ImmutableList<T>.Node.
This aligns the behavior with Array.IndexOf, which permits
index == Count provided count is 0.
CopilotAI
review requested due to automatic review settings
February 27, 2026 13:58
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Pull request overview
This PR fixes the IndexOf upper-bound validation in ImmutableArray<T>, ImmutableArray<T>.Builder, and ImmutableList<T>.Node to align with Array.IndexOf behavior, which allows startIndex == Count when count == 0. The PR is a follow-up to #124560 which fixed similar issues in LastIndexOf.
Changes:
  • Modified upper-bound validation for startIndex/index parameter from < Count to <= Count in IndexOf methods
  • Added upper-bound validation to ImmutableList<T>.Node.IndexOf which was previously missing
  • Enhanced tests to validate parameter names in thrown exceptions and added consistency tests with Array.IndexOf
Reviewed changes
Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.
Show a summary per file
FileDescription
ImmutableArray_1.csChanged startIndex upper-bound validation from < Length to <= Length in IndexOf
ImmutableArray_1.Builder.csChanged startIndex upper-bound validation from < Count to <= Count in IndexOf
ImmutableList_1.Node.csAdded upper-bound check to index validation (from single >= 0 check to >= 0 && <= Count), added redundant count upper-bound validation
IndexOfTests.csAdded indexParameterName parameter to test signature, enhanced tests to validate exception parameter names and added edge case tests
ImmutableArrayTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "startIndex" parameter
ImmutableArrayBuilderTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "startIndex" parameter
ImmutableListTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "index" parameter
ImmutableListBuilderTest.csUpdated test calls to pass "index" parameter
Comment thread...raries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList_1.Node.cs
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Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.
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Pull request overview
Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.
Comment threadsrc/libraries/System.Collections.Immutable/tests/IndexOfTests.cs
@prozolic
Update src/libraries/System.Collections.Immutable/tests/IndexOfTests.cs
ae3f07b
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
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Pull request overview
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@MihaZupan I've addressed your feedback. Could you please take another look when you get a chance?
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Comment threadsrc/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray_1.cs
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Comment thread...raries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList_1.Node.cs
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@MihaZupan
Handle index + count overflows
0a14ce3
Co-authored-by: Miha Zupan <mihazupan.zupan1@gmail.com>
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Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.
Comment thread...es/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray_1.Builder.cs
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Fix mixed CRLF/LF line endings in ImmutableArray_1.cs
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PR dotnet#124967 accidentally committed two lines with CRLF endings into
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Renormalize to consistent LF endings.
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Fix mixed CRLF/LF line endings in ImmutableArray_1.cs (#127159)
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PR #124967 accidentally committed two lines with CRLF endings into a
file that uses LF, causing git to perpetually report the file as
modified on Windows (core.autocrlf=true).
Renormalize to consistent LF endings.
cc: @MihaZupan
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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ImmutableArray<T>.IndexOf throws ArgumentOutOfRangeException when startIndex equals Length and count is 0


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injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
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var __m = "*";
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Fix IndexOf upper-bound guard in ImmutableArray/List - #124967
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Fix IndexOf upper-bound guard in ImmutableArray/List#124967
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Change the startIndex upper-bound validation in IndexOf from '< Count' to '<= Count' for ImmutableArray<T>,
ImmutableArray<T>.Builder, and add upper-bound validation in ImmutableList<T>.Node.

This aligns the behavior with Array.IndexOf, which permits index == Count provided count is 0.
Change:
  • Change the startIndex upper-bound validation in IndexOf from '< Count' to '<= Count' for ImmutableArray,
    ImmutableArray<T>.Builder.
  • Add upper-bound validation in ImmutableList<T>.Node to match the behavior of ImmutableArray<T>.
  • Add test case and fix test case to also validate the parameter name as the fix in Use Requires.Range in LastIndexOf #124560.
Fixes#124968
@prozolic
Fix IndexOf upper-bound guard in ImmutableArray/List
a338be4
Change the startIndex upper-bound validation in IndexOf from
'< Count' to '<= Count' for ImmutableArray<T>,
ImmutableArray<T>.Builder, and add upper-bound validation
in ImmutableList<T>.Node.
This aligns the behavior with Array.IndexOf, which permits
index == Count provided count is 0.
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Pull request overview
This PR fixes the IndexOf upper-bound validation in ImmutableArray<T>, ImmutableArray<T>.Builder, and ImmutableList<T>.Node to align with Array.IndexOf behavior, which allows startIndex == Count when count == 0. The PR is a follow-up to #124560 which fixed similar issues in LastIndexOf.
Changes:
  • Modified upper-bound validation for startIndex/index parameter from < Count to <= Count in IndexOf methods
  • Added upper-bound validation to ImmutableList<T>.Node.IndexOf which was previously missing
  • Enhanced tests to validate parameter names in thrown exceptions and added consistency tests with Array.IndexOf
Reviewed changes
Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.
Show a summary per file
FileDescription
ImmutableArray_1.csChanged startIndex upper-bound validation from < Length to <= Length in IndexOf
ImmutableArray_1.Builder.csChanged startIndex upper-bound validation from < Count to <= Count in IndexOf
ImmutableList_1.Node.csAdded upper-bound check to index validation (from single >= 0 check to >= 0 && <= Count), added redundant count upper-bound validation
IndexOfTests.csAdded indexParameterName parameter to test signature, enhanced tests to validate exception parameter names and added edge case tests
ImmutableArrayTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "startIndex" parameter
ImmutableArrayBuilderTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "startIndex" parameter
ImmutableListTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "index" parameter
ImmutableListBuilderTest.csUpdated test calls to pass "index" parameter
Comment thread...raries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList_1.Node.cs
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Pull request overview
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Pull request overview
Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.
Comment threadsrc/libraries/System.Collections.Immutable/tests/IndexOfTests.cs
@prozolic
Update src/libraries/System.Collections.Immutable/tests/IndexOfTests.cs
ae3f07b
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
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@MihaZupan I've addressed your feedback. Could you please take another look when you get a chance?
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Comment threadsrc/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray_1.cs
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Comment thread...raries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList_1.Node.cs
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@MihaZupan
Handle index + count overflows
0a14ce3
Co-authored-by: Miha Zupan <mihazupan.zupan1@gmail.com>
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Comment thread...es/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray_1.Builder.cs
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Pull request overview
Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.
@MihaZupan
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@svick
Fix mixed CRLF/LF line endings in ImmutableArray_1.cs
0615793
PR dotnet#124967 accidentally committed two lines with CRLF endings into
a file that uses LF, causing git to perpetually report the file as
modified on Windows (core.autocrlf=true).
Renormalize to consistent LF endings.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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@svick
Fix mixed CRLF/LF line endings in ImmutableArray_1.cs (#127159)
0f1536b
PR #124967 accidentally committed two lines with CRLF endings into a
file that uses LF, causing git to perpetually report the file as
modified on Windows (core.autocrlf=true).
Renormalize to consistent LF endings.
cc: @MihaZupan
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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ImmutableArray<T>.IndexOf throws ArgumentOutOfRangeException when startIndex equals Length and count is 0


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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
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Skip to content
Fix IndexOf upper-bound guard in ImmutableArray/List - #124967
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prozolic:indexof
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Fix IndexOf upper-bound guard in ImmutableArray/List#124967
MihaZupan merged 9 commits into
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edited by MihaZupan

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Change the startIndex upper-bound validation in IndexOf from '< Count' to '<= Count' for ImmutableArray<T>,
ImmutableArray<T>.Builder, and add upper-bound validation in ImmutableList<T>.Node.

This aligns the behavior with Array.IndexOf, which permits index == Count provided count is 0.
Change:
  • Change the startIndex upper-bound validation in IndexOf from '< Count' to '<= Count' for ImmutableArray,
    ImmutableArray<T>.Builder.
  • Add upper-bound validation in ImmutableList<T>.Node to match the behavior of ImmutableArray<T>.
  • Add test case and fix test case to also validate the parameter name as the fix in Use Requires.Range in LastIndexOf #124560.
Fixes#124968
@prozolic
Fix IndexOf upper-bound guard in ImmutableArray/List
a338be4
Change the startIndex upper-bound validation in IndexOf from
'< Count' to '<= Count' for ImmutableArray<T>,
ImmutableArray<T>.Builder, and add upper-bound validation
in ImmutableList<T>.Node.
This aligns the behavior with Array.IndexOf, which permits
index == Count provided count is 0.
CopilotAI
review requested due to automatic review settings
February 27, 2026 13:58
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Pull request overview
This PR fixes the IndexOf upper-bound validation in ImmutableArray<T>, ImmutableArray<T>.Builder, and ImmutableList<T>.Node to align with Array.IndexOf behavior, which allows startIndex == Count when count == 0. The PR is a follow-up to #124560 which fixed similar issues in LastIndexOf.
Changes:
  • Modified upper-bound validation for startIndex/index parameter from < Count to <= Count in IndexOf methods
  • Added upper-bound validation to ImmutableList<T>.Node.IndexOf which was previously missing
  • Enhanced tests to validate parameter names in thrown exceptions and added consistency tests with Array.IndexOf
Reviewed changes
Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.
Show a summary per file
FileDescription
ImmutableArray_1.csChanged startIndex upper-bound validation from < Length to <= Length in IndexOf
ImmutableArray_1.Builder.csChanged startIndex upper-bound validation from < Count to <= Count in IndexOf
ImmutableList_1.Node.csAdded upper-bound check to index validation (from single >= 0 check to >= 0 && <= Count), added redundant count upper-bound validation
IndexOfTests.csAdded indexParameterName parameter to test signature, enhanced tests to validate exception parameter names and added edge case tests
ImmutableArrayTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "startIndex" parameter
ImmutableArrayBuilderTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "startIndex" parameter
ImmutableListTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "index" parameter
ImmutableListBuilderTest.csUpdated test calls to pass "index" parameter
Comment thread...raries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList_1.Node.cs
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Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.
Comment threadsrc/libraries/System.Collections.Immutable/tests/IndexOfTests.cs
@prozolic
Update src/libraries/System.Collections.Immutable/tests/IndexOfTests.cs
ae3f07b
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
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@MihaZupan I've addressed your feedback. Could you please take another look when you get a chance?
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Comment threadsrc/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray_1.cs
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Comment thread...raries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList_1.Node.cs
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@MihaZupan
Handle index + count overflows
0a14ce3
Co-authored-by: Miha Zupan <mihazupan.zupan1@gmail.com>
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Comment thread...es/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray_1.Builder.cs
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Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.
@MihaZupan
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@svick
Fix mixed CRLF/LF line endings in ImmutableArray_1.cs
0615793
PR dotnet#124967 accidentally committed two lines with CRLF endings into
a file that uses LF, causing git to perpetually report the file as
modified on Windows (core.autocrlf=true).
Renormalize to consistent LF endings.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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@svick
Fix mixed CRLF/LF line endings in ImmutableArray_1.cs (#127159)
0f1536b
PR #124967 accidentally committed two lines with CRLF endings into a
file that uses LF, causing git to perpetually report the file as
modified on Windows (core.autocrlf=true).
Renormalize to consistent LF endings.
cc: @MihaZupan
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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ImmutableArray<T>.IndexOf throws ArgumentOutOfRangeException when startIndex equals Length and count is 0


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, 'i');
if (__m === '*' || __re.test(location.href)) {
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Fix IndexOf upper-bound guard in ImmutableArray/List - #124967
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prozolic:indexof
Apr 19, 2026
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Fix IndexOf upper-bound guard in ImmutableArray/List#124967
MihaZupan merged 9 commits into
dotnet:mainfrom 
prozolic:indexof
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Feb 27, 2026•

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Change the startIndex upper-bound validation in IndexOf from '< Count' to '<= Count' for ImmutableArray<T>,
ImmutableArray<T>.Builder, and add upper-bound validation in ImmutableList<T>.Node.

This aligns the behavior with Array.IndexOf, which permits index == Count provided count is 0.
Change:
  • Change the startIndex upper-bound validation in IndexOf from '< Count' to '<= Count' for ImmutableArray,
    ImmutableArray<T>.Builder.
  • Add upper-bound validation in ImmutableList<T>.Node to match the behavior of ImmutableArray<T>.
  • Add test case and fix test case to also validate the parameter name as the fix in Use Requires.Range in LastIndexOf #124560.
Fixes#124968
@prozolic
Fix IndexOf upper-bound guard in ImmutableArray/List
a338be4
Change the startIndex upper-bound validation in IndexOf from
'< Count' to '<= Count' for ImmutableArray<T>,
ImmutableArray<T>.Builder, and add upper-bound validation
in ImmutableList<T>.Node.
This aligns the behavior with Array.IndexOf, which permits
index == Count provided count is 0.
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February 27, 2026 13:58
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Pull request overview
This PR fixes the IndexOf upper-bound validation in ImmutableArray<T>, ImmutableArray<T>.Builder, and ImmutableList<T>.Node to align with Array.IndexOf behavior, which allows startIndex == Count when count == 0. The PR is a follow-up to #124560 which fixed similar issues in LastIndexOf.
Changes:
  • Modified upper-bound validation for startIndex/index parameter from < Count to <= Count in IndexOf methods
  • Added upper-bound validation to ImmutableList<T>.Node.IndexOf which was previously missing
  • Enhanced tests to validate parameter names in thrown exceptions and added consistency tests with Array.IndexOf
Reviewed changes
Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.
Show a summary per file
FileDescription
ImmutableArray_1.csChanged startIndex upper-bound validation from < Length to <= Length in IndexOf
ImmutableArray_1.Builder.csChanged startIndex upper-bound validation from < Count to <= Count in IndexOf
ImmutableList_1.Node.csAdded upper-bound check to index validation (from single >= 0 check to >= 0 && <= Count), added redundant count upper-bound validation
IndexOfTests.csAdded indexParameterName parameter to test signature, enhanced tests to validate exception parameter names and added edge case tests
ImmutableArrayTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "startIndex" parameter
ImmutableArrayBuilderTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "startIndex" parameter
ImmutableListTest.csAdded IndexOfConsistentWithArray test and updated test calls to pass "index" parameter
ImmutableListBuilderTest.csUpdated test calls to pass "index" parameter
Comment thread...raries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList_1.Node.cs
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Pull request overview
Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.
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Pull request overview
Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.
Comment threadsrc/libraries/System.Collections.Immutable/tests/IndexOfTests.cs
@prozolic
Update src/libraries/System.Collections.Immutable/tests/IndexOfTests.cs
ae3f07b
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
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Pull request overview
Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.
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@MihaZupan I've addressed your feedback. Could you please take another look when you get a chance?
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Comment threadsrc/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray_1.cs
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Comment thread...raries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList_1.Node.cs
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@MihaZupan
Handle index + count overflows
0a14ce3
Co-authored-by: Miha Zupan <mihazupan.zupan1@gmail.com>
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Pull request overview
Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.
Comment thread...es/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray_1.Builder.cs
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Pull request overview
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@MihaZupan
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@svick
Fix mixed CRLF/LF line endings in ImmutableArray_1.cs
0615793
PR dotnet#124967 accidentally committed two lines with CRLF endings into
a file that uses LF, causing git to perpetually report the file as
modified on Windows (core.autocrlf=true).
Renormalize to consistent LF endings.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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Fix mixed CRLF/LF line endings in ImmutableArray_1.cs (#127159)
0f1536b
PR #124967 accidentally committed two lines with CRLF endings into a
file that uses LF, causing git to perpetually report the file as
modified on Windows (core.autocrlf=true).
Renormalize to consistent LF endings.
cc: @MihaZupan
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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ImmutableArray<T>.IndexOf throws ArgumentOutOfRangeException when startIndex equals Length and count is 0


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