ptx: fix panic caused by improper assert

[WhateverAWS]

fixes #10893

[ChrisDryden]

Would it be possible to add a test case for the example in the issue?

[ChrisDryden]

I think this doesn't fully resolve the issue, we're still using before.len() and after.len() instead of the chars.count in the head and tail chunk calculation

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/tty/tty-eof (fails in this run but passes in the 'main' branch)
Congrats! The gnu test tests/pr/bounded-memory is no longer failing!
Congrats! The gnu test tests/csplit/csplit-heap is now passing!
Congrats! The gnu test tests/cut/bounded-memory is now passing!
Congrats! The gnu test tests/rm/many-dir-entries-vs-OOM is now passing!

[WhateverAWS]

I think this doesn't fully resolve the issue, we're still using before.len() and after.len() instead of the chars.count in the head and tail chunk calculation

Ah yeah that make sense.

[oech3]

No need to fix everything at 1 PR.

[sylvestre]

but please still provide a test :)

[oech3]

Any progress?

[sylvestre]

LGTM — before.len() counts bytes, not characters. Using .chars().count() is the correct fix for multi-byte input.

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/misc/tty-eof (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/date/date-locale-hour (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/pr/bounded-memory (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tail/tail-n0f (passes in this run but fails in the 'main' branch)

[sylvestre]

needs a test

[sylvestre]

i will fix it in a follow up pr