From 96eb2e31a192968c376ce74ca5ab09c094d1d082 Mon Sep 17 00:00:00 2001
From: Daniel Shahaf <d.s@daniel.shahaf.name>
Date: Fri, 3 Apr 2020 01:19:38 +0000
Subject: [PATCH] driver: Fix "_zsh_highlight:3: read-only variable: ret"
 warnings when POSIX_BUILTINS is set.

Fixes #719.

Cf. #688.
---
 zsh-syntax-highlighting.zsh | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/zsh-syntax-highlighting.zsh b/zsh-syntax-highlighting.zsh
index a87a63c..7944b0f 100644
--- a/zsh-syntax-highlighting.zsh
+++ b/zsh-syntax-highlighting.zsh
@@ -72,7 +72,9 @@ typeset -ga ZSH_HIGHLIGHT_HIGHLIGHTERS
 _zsh_highlight()
 {
   # Store the previous command return code to restore it whatever happens.
-  readonly ret=$?
+  local ret=$?
+  # Make it read-only.  Can't combine this with the previous line when POSIX_BUILTINS may be set.
+  typeset -r ret
 
   # Remove all highlighting in isearch, so that only the underlining done by zsh itself remains.
   # For details see FAQ entry 'Why does syntax highlighting not work while searching history?'.