fix(spec): rework zsh completion mock around vared+zpty crash

`vared -c tmp` inside `zpty {,}myfn` aborts with `free(): invalid
pointer` on glibc-based zsh 5.9 builds (Ubuntu 24.04, recent Homebrew),
so every zsh case in `mock_spec.cr` returned the abort string instead of
completions. Spawning a fresh `zsh -i -c 'source <file>'` inside the
zpty gives ZLE its own interactive session and avoids the heap
corruption. The completion setup is materialized to a tempfile so the
inner shell can pick it up.

Also drop the outer EXIT/signal trap: `zpty` propagates inherited traps
to its child, and after the first iteration that child runs the trap on
exit and deletes the source file the next iteration still needs.
Cleanup now runs once after the loop instead.

Tighten up the delimiter parser too — using `==` substring matches and
keeping the post-D_OPN remainder in `PTY_LINES` makes the unambiguous
single-match path work without a leading blank line.

Author: claude

src/tabular/shell/zsh.ecr

@@ -1,59 +1,73 @@
 # SEE: https://unix.stackexchange.com/questions/668618/how-to-write-automated-tests-for-zsh-completion/668827#668827
+#
+# Background:
+#   The Stack Exchange recipe runs `vared -c tmp` inside `zpty {,}fn`, but on
+#   glibc-based zsh 5.9 builds (Ubuntu 24.04, Debian sid, recent Homebrew)
+#   that combination corrupts the heap and the pty emits `free(): invalid
+#   pointer` instead of any completions. Spawning a fresh interactive
+#   `zsh -i -c 'source <file>'` inside the zpty gives ZLE its own session and
+#   sidesteps the crash. We also avoid an EXIT trap on the outer shell — zpty
+#   propagates inherited traps to the child, so an outer cleanup trap would
+#   delete the source file out from under the next iteration.
 autoload -U compinit
-compinit
+compinit -u
 
 <% completers.each do |comp| -%>
 eval "$(<%= comp %> completion <%= bin %>)"
+<% end %>
+
+INNER=$(mktemp -p /var/tmp tabular_<%= pty %>.XXXXXX) || exit 1
+{
+	print -r -- 'autoload -U compinit'
+	print -r -- 'compinit -u'
+<% completers.each do |comp| -%>
+	print -r -- 'eval "$(<%= comp %> completion <%= bin %>)"'
 <% end -%>
+	print -r -- 'D_OPN=$'\''\C-B'\'
+	print -r -- 'D_CLS=$'\''\C-C'\'
+	print -r -- 'zstyle ":completion:*" max-matches-width 10'
+	print -r -- 'zstyle ":completion:*" list-colors ""'
+	print -r -- 'zle -C {,,}complete-word'
+	print -r -- 'complete-word () {'
+	print -r -- '  unset "compstate[vared]"'
+	print -r -- '  compstate[insert]=menu'
+	print -r -- '  compadd -x "${D_OPN}"'
+	print -r -- '  _main_complete "$@"'
+	print -r -- '  if [ -n "$compstate[unambiguous]" ] && [ "$compstate[nmatches]" = "1" ]; then'
+	print -r -- '    result=${compstate[unambiguous]/#$BASH_REMATCH}'
+	print -r -- '    echo -e "${D_OPN}\n${result}\n${D_CLS}"'
+	print -r -- '  fi'
+	print -r -- '  compadd -J -last- -x "${D_CLS}"'
+	print -r -- '  exit'
+	print -r -- '}'
+	print -r -- 'bindkey "^I" complete-word'
+	print -r -- 'vared -c tmp'
+} > "${INNER}"
+
+D_OPN=$'\C-B'
+D_CLS=$'\C-C'
 
-compmock () {
-  export D_OPN=$'\C-B'
-  export D_CLS=$'\C-C'
-
-  <%= pty %> () {
-    zstyle ':completion:*' max-matches-width 10 # Ensure alt-names on separate rows
-    zstyle ':completion:*' list-colors '' # Disable colouring
-
-    # Bind a custom widget to TAB.
-    bindkey '^I' complete-word
-    zle -C {,,}complete-word
-    complete-word () {
-      unset 'compstate[vared]' # Disguise a "normal" command-line
-      compstate[insert]=menu # Ensure menu is always displayed
-      compadd -x "${D_OPN}" # Open delimiter
-      _main_complete "$@" # Run completion
-      # Intercept unambiguous match
-      if [ -n "$compstate[unambiguous]" ] && [ "$compstate[nmatches]" = '1' ]; then
-        result=${compstate[unambiguous]/#$BASH_REMATCH}
-        echo -e "${D_OPN}\n${result}\n${D_CLS}"
-      fi
-      compadd -J -last- -x "${D_CLS}" # close delimiter
-      exit
-    }
-
-    vared -c tmp # Start line editor
-  }
-
-  zmodload zsh/zpty  # Load the pseudo terminal module.
-	trap 'zpty -d' ABRT EXIT HUP INT QUIT TERM  # Delete the pty.
-
-	while read -r -t10 -A ARGS; do
-		zpty {,}<%= pty %>   # Create a new pty and run our function in it.
-		zpty -w -n <%= pty %> "$1 $ARGS[*]"$'\t'  # Simulate a command being typed and tabbed.
-
-		# Capture terminal output
-		PTY_LINES=()
-		while zpty -r <%= pty %> REPLY; do
-			[[ "${REPLY}" =~ "${D_CLS}" ]] && break
-			[[ "${REPLY}" =~ "${D_OPN}" ]] \
-				&& PTY_LINES=() \
-				|| PTY_LINES+=("${REPLY%%$'\n'}")
-		done
-
-		print -nrC1 -- "${PTY_LINES[@]}" | sed -r -e 's/\x1b\[[0-9;]*m?//g' -e 's/\r//g' -e 's/ *$//g'
-    print -n -- $'\C-@'
-    zpty -d <%= pty %>
+zmodload zsh/zpty
+
+while read -r -t10 -A ARGS; do
+	zpty <%= pty %> "zsh -i -c 'source ${INNER}'"
+	zpty -w -n <%= pty %> "<%= prog %> ${ARGS[*]}"$'\t'
+
+	PTY_LINES=()
+	while zpty -r <%= pty %> REPLY; do
+		[[ "${REPLY}" == *"${D_CLS}"* ]] && break
+		if [[ "${REPLY}" == *"${D_OPN}"* ]]; then
+			REPLY="${REPLY##*${D_OPN}}"
+			PTY_LINES=()
+		fi
+		PTY_LINES+=("${REPLY%%$'\n'}")
 	done
-}
 
-compmock <%= prog %>
+	print -nrC1 -- "${PTY_LINES[@]}" \
+		| sed -r -e 's/\x1b\[[0-9;]*m?//g' -e 's/\r//g' -e 's/ *$//g' \
+		| sed '/^$/d'
+	print -n -- $'\C-@'
+	zpty -d <%= pty %>
+done
+
+rm -f "${INNER}"