On Linux, tab completion doesn't show files whose names differ from others by case only

Note: The problem seems to be in the match-cycling logic, because TabExpansion2 is working properly.

Steps to reproduce

On Linux:

# Switch to a temp dir.
Push-Location (New-Item -Type Directory -Force "temp:/$PID")

# Create two files whose names differ only in case.
$null = New-Item foo.txt, FOO.txt

# Note that the following test SUCCEEDS.
# That is, the TabExpansion2 function correctly finds both names.
(TabExpansion2 './').CompletionMatches.CompletionText | Should -Be './foo.txt', './FOO.txt'

# However,  INTERACTIVE CYCLING is broken.
# Type "./" and press TAB to cycle through the matches.
# Currently only *1* name is found.

Code for later cleanup:

Pop-Location;  Remove-Item -Recurse "temp:/$PID"

Expected behavior

Tab-completion should cycle through ./foo.txt and /FOO.txt.

Actual behavior

Only one name is found, ./foo.txt

Environment data

PowerShell Core 7.2.0-preview.1

[MartinGC94]

@dkaszews Neat. I just tested it on my Windows 11 PC and it works without issues if you unload the PSReadline module so if there was any doubt before that the issue was caused by PSReadline then that doubt should be cleared now.

[dkaszews]

Will see if changing the line found by @MartinGC94 to check if system is case insensitive (Windows) or case sensitive (mostly everything else) resolves the issue without breaking any tests.