fix(hooks): replace run-hook.cmd heredoc with :; label lines (#571)

bash >= 5.1 writes heredocs into a pipe pre-fork; under macOS pipe
pressure the kernel hands out 512-byte pipes and the wrapper's 1.4KB
CMDBLOCK heredoc deadlocks every hook. Label lines parse nowhere:
cmd.exe skips them as labels, POSIX shells exec away before the batch
block. Also: silent fail-open when bash or the script name is missing,
and CDPATH-proof directory resolution.
This commit is contained in:
Drew Ritter
2026-08-05 15:12:47 -07:00
parent 431915accb
commit d80fc1808a
2 changed files with 24 additions and 11 deletions

View File

@@ -1,8 +1,20 @@
: << 'CMDBLOCK'
:; command -v bash >/dev/null 2>&1 || exit 0
:; [ $# -ge 1 ] || exit 0
:; SCRIPT_DIR="$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)"
:; SCRIPT_NAME="$1"; shift; exec bash "${SCRIPT_DIR}/${SCRIPT_NAME}" "$@"
@echo off
REM Cross-platform polyglot wrapper for hook scripts.
REM On Windows: cmd.exe runs the batch portion, which finds and calls bash.
REM On Unix: the shell interprets this as a script (: is a no-op in bash).
REM On Unix: POSIX shells execute the ":;" lines above and exec away before
REM reaching this batch block (":" is a no-op; cmd.exe treats lines starting
REM with ":" as labels and skips them). If bash or the script name is
REM missing, the wrapper exits 0 silently - hooks are optional context, never
REM a session breaker.
REM On Windows: cmd.exe runs this batch portion, which finds and calls bash.
REM
REM Heredocs are banned in this file and every hooks/ executable: bash 5.1+
REM delivers them via a pre-fork pipe write that deadlocks on macOS under
REM pipe pressure (issue #571). tests/hooks/test-no-heredocs-in-hooks.sh is
REM the fence.
REM
REM Hook scripts use extensionless filenames (e.g. "session-start" not
REM "session-start.sh") so Claude Code's Windows auto-detection -- which
@@ -35,12 +47,4 @@ if %ERRORLEVEL% equ 0 (
)
REM No bash found - exit silently rather than error
REM (plugin still works, just without SessionStart context injection)
exit /b 0
CMDBLOCK
# Unix: run the named script directly
SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
SCRIPT_NAME="$1"
shift
exec bash "${SCRIPT_DIR}/${SCRIPT_NAME}" "$@"

View File

@@ -184,6 +184,15 @@ assert_command_output \
CLAUDE_PLUGIN_ROOT="$REPO_ROOT" \
bash "$WRAPPER_UNDER_TEST" session-start
# With no bash available, the wrapper must fail open: silent, exit 0.
if output="$(env -i PATH=/nonexistent /bin/sh "$WRAPPER_UNDER_TEST" session-start 2>&1)" \
&& [ -z "$output" ]; then
pass "wrapper with no bash on PATH is silent and exits 0"
else
fail "wrapper with no bash on PATH is silent and exits 0"
printf '%s\n' "$output" | head -3 | sed 's/^/ /'
fi
cursor_home="$(make_home cursor)"
assert_command_output \
"Cursor emits top-level additional_context only" \