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Luan Taraschi
cdb8a8dd83
`"a\tb".expandtabs(0)` panicked with a capacity overflow. CPython returns `'ab'`: with no width to advance to, the tabs come out and nothing else moves. `expandtabs(-1)` is the same call, since `ExpandTabsArgs::tabsize` sends every negative value to 0. `expandtabs` keeps the tab stop in `tab_size` and the current column in `col_count`, and on a tab it does `tab_size - col_count`. With a tab size of zero both start at 0, the first character makes `col_count` 1 while `tab_size` stays 0, and the subtraction underflows. The run of spaces asked for next is `usize::MAX`, and the allocation aborts the process. A tab has to follow something on the line to reach it: `"\ta".expandtabs(0)` subtracts 0 from 0 and comes out right by accident. `BytesInner::expandtabs` already returns early for this and filters the tabs out. The string version now does the same. Assisted-by: Claude Code:claude-opus-5
Test snippets
This directory contains two sets of test snippets which can be run in Python.
The snippets/ directory contains functional tests, and the benchmarks/
directory contains snippets for use in benchmarking RustPython's performance.
Setup
Our testing depends on pytest, which you can install using pip.
Running
Simply run pytest -v in this directory, and the tests should run (and hopefully
pass). If it hangs for a long time, that's because it's building RustPython in
release mode, which should take less time than it would to run every test
snippet with RustPython compiled in debug mode.