fix: Overflow error in Commit Dialog

[palver123]

DiffViewerLineNumberControl did not handle when MaxLineNumber was 0. Either an empty file can cause this (in this case _diffLines is empty so no problem) or a file where diff hunks were lost due to encoding errors.

Fixes #7023

Proposed changes

Change the current getter:

if (_visible && _diffLines.Any())
{
    int maxDigits = (int)Math.Log10(MaxLineNumber) + 1;
    return ...;
}

to

if (_visible && _diffLines.Any())
{
    int maxDigits = MaxLineNumber > 0 ?  ((int)Math.Log10(MaxLineNumber) + 1) : 0;
    return ...;
}

Test methodology

Tested manually.

Test environment(s)

• Git 2.22.0.windows.1
• Microsoft Windows NT 10.0.17134.0
• .NET Framework 4.7.3416.0

✒️ I contribute this code under The Developer Certificate of Origin.

[RussKie]

Please send your sign off to contributors.txt in a separate PR. Thanks

[palver123]

I've updated contributors.txt in #7061

[pmiossec]

Thanks.