Adds a new rule to scripts/check-windows-footguns.py that flags
subprocess.run/Popen/call/check_output/check_call(..., text=True, ...) calls
missing an explicit encoding= kwarg.
On Chinese Windows (cp936/GBK) and other non-UTF-8 default codepages,
text=True without encoding= decodes child output with
locale.getpreferredencoding(False), crashing _readerthread with
UnicodeDecodeError on non-default-codepage bytes (issues #47939, #53428,
rule prevents future regressions.
Rule design:
- Pattern matches 'text=True' / 'text = True'
- post_filter skips lines that:
- already pass encoding= on the same line
- are method definitions (def text)
- contain text=True inside string literals
- are not subprocess-shaped calls (heuristic via _is_likely_subprocess_call)
- Two helper functions: _is_likely_subprocess_call, _looks_like_string_literal
- Multi-line calls where subprocess.X( and text=True are on different lines
are not flagged (acceptable false negative for a line-based scanner)
Also fixes the linter's own footgun: get_staged_files() and get_diff_files()
used subprocess.check_output(text=True) without encoding= — now fixed.
Suppresses 4 false positives on non-Windows platform-exclusive calls:
- tools/voice_mode.py (Termux/Android)
- tools/environments/singularity.py (Linux HPC)
- plugins/google_meet/cli.py (macOS system_profiler)
Test plan:
- 21 unit tests in tests/scripts/test_footgun_subprocess_encoding.py
- TestDetection: 6 cases verifying the rule flags real subprocess calls
- TestSuppression: 7 cases verifying false-positive avoidance
- TestHelpers: 7 cases for the two helper functions
- TestFullRepoScan: scans the whole tree and asserts the new rule finds
only the 7 call sites that PR #60741 fixes (or zero, once #60741 merges)
Verified: full-repo scan reports 7 matches on main (the #60741 sites),
4 platform-exclusive calls correctly suppressed, zero false positives.
