perf: fix O(n²) catastrophic backtracking in redact regex (salvage #4779)#4962
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perf: fix O(n²) catastrophic backtracking in redact regex (salvage #4779)#4962
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…ile read guard
Two pre-existing issues causing test_file_read_guards timeouts on CI:
1. agent/redact.py: _ENV_ASSIGN_RE used unbounded [A-Z_]* with
IGNORECASE, matching any letter/underscore to end-of-string at
each position → O(n²) backtracking on 100K+ char inputs.
Bounded to {0,50} since env var names are never that long.
2. tools/file_tools.py: redact_sensitive_text() ran BEFORE the
character-count guard, so oversized content (that would be rejected
anyway) went through the expensive regex first. Reordered to check
size limit before redaction.
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Salvage of PR #4779 by @acsezen. Cherry-picked with authorship preserved.
Fixes
Regex bound (
agent/redact.py):[A-Z_]*→[A-Z_]{0,50}in_ENV_ASSIGN_RE. Eliminates O(n²) catastrophic backtracking on large uniform strings. Benefits all callers (file_tools, terminal_tool, browser_tool, code_execution_tool).Guard reorder (
tools/file_tools.py): Character-count guard now runs beforeredact_sensitive_text(). Oversized content rejected immediately without touching the regex.Results
Closes #4779