(sh-font-lock-keywords): Don't crash for an unrecognized shell.

diff --git a/lisp/progmodes/sh-script.el b/lisp/progmodes/sh-script.el
index eec351c5cc49f8493a43c3511fa461d8d520d3a0..53e9d6ab151cf8f7c5ad1229b373487fef93f263 100644 (file)
--- a/lisp/progmodes/sh-script.el
+++ b/lisp/progmodes/sh-script.el
@@ -794,11 +794,12 @@ with your script for an edit-interpret-debug cycle."
   "Function to get simple fontification based on `sh-font-lock-keywords'.
 This adds rules for comments and assignments."
   (sh-feature sh-font-lock-keywords
-             (lambda (list)
-               `((,(sh-feature sh-assignment-regexp)
-                  1 font-lock-variable-name-face)
-                 ,@keywords
-                 ,@list))))
+             (when (stringp (sh-feature sh-assignment-regexp))
+               (lambda (list)
+                 `((,(sh-feature sh-assignment-regexp)
+                    1 font-lock-variable-name-face)
+                   ,@keywords
+                   ,@list)))))
 
 (defun sh-font-lock-keywords-1 (&optional builtins)
   "Function to get better fontification including keywords."