[C++] Signed to unsigned integer cast yields incorrect results when type sizes are the same

[asfimport]

In https://github.com/apache/arrow/blob/master/cpp/src/arrow/compute/kernels/cast.cc#L239, an int32_t is overflows in

constexpr in_type kMax = static_cast<in_type>(std::numeric_limits<out_type>::max());

resulting in safety checks not being correctly performed

In [2]: arr = pa.array([-1, -2, -3], type='int32')

In [3]: arr.cast('uint32')
Out[3]: 
<pyarrow.lib.UInt32Array object at 0x7f4889457b88>
[
  4294967295,
  4294967294,
  4294967293
]

This would be expected to error when safe=True

Reporter: Wes McKinney / @wesm
Assignee: Francois Saint-Jacques / @fsaintjacques

PRs and other links:

• GitHub Pull Request #3022

_{Note: This issue was originally created as ARROW-3790. Please see the migration documentation for further details.}

[asfimport]

Francois Saint-Jacques / @fsaintjacques:
I'm currently working on this, the problem turned out to be a bigger than expected. While the pointed line is indeed wrong, the actual problem lies somewhere else. @wesm can you assign this task to me?

[asfimport]

Wes McKinney / @wesm:
Just added you as a contributor, so you can assign yourself issues now

[asfimport]

Wes McKinney / @wesm:
Issue resolved by pull request 3022
#3022