ptx: journalctl -b > a; ptx a panics

[oech3]

$ ptx a

thread 'main' (10281) panicked at src/uu/ptx/src/ptx.rs:490:5:
assertion failed: max_before_size >= before.len()
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

[oech3]

@cakebaker Is this really dupe? Boot message does not have emoji, but could have kanji.

[cakebaker]

The panic is on the same line in both issues and so I think a fix for #10893 will also fix this issue.

[oech3]

The panic is on the same line

Oh it is useful