fix: don't name shell variables "path" - zsh ties it to $PATH

test/helpers.bash

@@ -25,7 +25,8 @@ wt_common_setup() {
   while [ ! -f "$dir/wt.sh" ] && [ "$dir" != "/" ]; do
     dir=$(dirname "$dir")
   done
-  source "$dir/wt.sh"
+  WT_SH="$dir/wt.sh"
+  source "$WT_SH"
 }
 
 wt_common_teardown() {

test/zsh.bats

@@ -0,0 +1,28 @@
+load helpers
+
+setup()    { wt_common_setup; }
+teardown() { wt_common_teardown; }
+
+# zsh ties the `path` array to $PATH, so a `local path` (or a bare
+# `read -r path`) inside a function empties PATH for that function and
+# everything it calls - git/awk stop resolving mid-run. bash ignores this
+# entirely, so the behavioural test has to run under a real zsh.
+
+@test "wt merged --rm works under zsh (PATH not clobbered by a 'path' local)" {
+  command -v zsh >/dev/null || skip "zsh not installed"
+  git -C "$TEST_REPO" merge -q feature
+
+  run zsh -c "cd '$TEST_REPO'; source '$WT_SH'; wt merged --rm -y"
+  [ "$status" -eq 0 ]
+  [[ "$output" != *"git: command not found"* ]]
+  [[ "$output" != *"command not found: git"* ]]
+  [[ "$output" != *"no worktree matching"* ]]
+  [ ! -d "$TEST_REPO-feature" ]
+}
+
+# static guard: catches new occurrences in any function, including ones with
+# no zsh test coverage. WT_PATH (the hook env var) is not a special name.
+@test "no shell variable is named 'path'" {
+  run grep -nE '(^|[[:space:];])(local|typeset)[^=]*[[:space:]]path([[:space:]=]|$)|read([[:space:]]+-[^[:space:]]+)*[[:space:]]+path([[:space:]]|$)' "$WT_SH"
+  [ "$status" -ne 0 ]
+}

wt.sh

@@ -44,9 +44,8 @@ _wt_ls() {
 }
 
 # resolve claude/jq/column to absolute paths up front and fetch the full
-# session list once. Some versions of `claude` mutate the calling shell's
-# PATH as a side effect, so every lookup must happen before the first call
-# to it - sets _WT_CLAUDE_BIN / _WT_JQ_BIN / _WT_COLUMN_BIN / _WT_CLAUDE_JSON.
+# session list once - sets _WT_CLAUDE_BIN / _WT_JQ_BIN / _WT_COLUMN_BIN /
+# _WT_CLAUDE_JSON.
 # Returns 0 on success, 1 if `claude` is missing (non-fatal, caller falls
 # back to its normal output), 2 if `jq` is missing (fatal).
 _wt_claude_init() {
@@ -96,13 +95,14 @@ _wt_claude_table() {
   local main_wt
   main_wt=$(git worktree list --porcelain | awk '/^worktree /{print $2; exit}')
 
-  local path branch display_branch sessions rows
+  # NB: never name a shell variable "path" - zsh ties it to $PATH
+  local wt_path branch display_branch sessions rows
   rows="BRANCH"$'\t'"SESSION"$'\t'"NAME"$'\t'"STATE"$'\n'
-  while IFS=$'\t' read -r path branch; do
-    [ -z "$path" ] && continue
+  while IFS=$'\t' read -r wt_path branch; do
+    [ -z "$wt_path" ] && continue
     display_branch="$branch"
-    [ "$path" = "$main_wt" ] && display_branch="(main, branch varies)"
-    sessions=$(printf '%s' "$_WT_CLAUDE_JSON" | "$_WT_JQ_BIN" -r --arg wt "$path" \
+    [ "$wt_path" = "$main_wt" ] && display_branch="(main, branch varies)"
+    sessions=$(printf '%s' "$_WT_CLAUDE_JSON" | "$_WT_JQ_BIN" -r --arg wt "$wt_path" \
       '.[] | select(.cwd == $wt) | [.id, (.name // "-"), .state] | @tsv')
     if [ -z "$sessions" ]; then
       rows+="$display_branch"$'\t'"-"$'\t'"-"$'\t'"-"$'\n'
@@ -123,8 +123,8 @@ _wt_claude_table() {
 # delete the Claude Code sessions recorded against a worktree path (claude rm);
 # expects _wt_claude_init to have been run already
 _wt_claude_rm_sessions() {
-  local path="$1" rc=0 ids id
-  ids=$(printf '%s' "$_WT_CLAUDE_JSON" | "$_WT_JQ_BIN" -r --arg wt "$path" \
+  local wt_path="$1" rc=0 ids id
+  ids=$(printf '%s' "$_WT_CLAUDE_JSON" | "$_WT_JQ_BIN" -r --arg wt "$wt_path" \
     '.[] | select(.cwd == $wt) | .id // empty')
   [ -z "$ids" ] && return 0
   while IFS= read -r id; do
@@ -158,13 +158,13 @@ _wt_run_hook() {
 
 # run an ad-hoc hook script passed via --pre-hook / --post-hook
 _wt_run_adhoc_hook() {
-  local file="$1" branch="$2" path="$3"
+  local file="$1" branch="$2" wt_path="$3"
   [ -n "$file" ] || return 0
   [ -e "$file" ] || { echo "wt: hook file not found: $file" >&2; return 1; }
   if [ -x "$file" ]; then
-    WT_BRANCH="$branch" WT_PATH="$path" "$file"
+    WT_BRANCH="$branch" WT_PATH="$wt_path" "$file"
   else
-    WT_BRANCH="$branch" WT_PATH="$path" bash "$file"
+    WT_BRANCH="$branch" WT_PATH="$wt_path" bash "$file"
   fi
 }
 
@@ -330,11 +330,13 @@ _wt_merged() {
   fi
 
   # never remove the main working tree, even if it's on a merged branch
-  local main_wt path branch failed=0
+  # NB: never name a shell variable "path" - zsh ties it to $PATH, so a
+  # `local path` (or a bare `read -r path`) wipes PATH for everything below
+  local main_wt wt_path branch failed=0
   main_wt=$(git worktree list --porcelain | awk '/^worktree /{print $2; exit}')
-  while IFS=$'\t' read -r path branch; do
-    [ -z "$path" ] && continue
-    if [ "$path" = "$main_wt" ]; then
+  while IFS=$'\t' read -r wt_path branch; do
+    [ -z "$wt_path" ] && continue
+    if [ "$wt_path" = "$main_wt" ]; then
       echo "wt: skipping main worktree [$branch]" >&2
       continue
     fi