* lisp/shell.el (shell--unquote&requote-argument): Match data misuse

* lisp/shell.el (shell--unquote&requote-argument): Fix
off-by-one thinko.  Don't use match data after a failed string-match.

1 files changed, 7 insertions, 3 deletions

diff --git a/lisp/shell.el b/lisp/shell.el
index 1f019f20f3a..34bd77282ab 100644
--- a/lisp/shell.el
+++ b/lisp/shell.el
@@ -384,11 +384,15 @@ Thus, this does not include the shell's current directory.")
        ((eq (aref qstr match) ?\") (setq dquotes (not dquotes)))
        ((eq (aref qstr match) ?\')
         (cond
+         ;; Treat single quote as text if inside double quotes.
          (dquotes (funcall push "'" (match-end 0)))
-         ((< match (1+ (length qstr)))
+         ((< (1+ match) (length qstr))
           (let ((end (string-match "'" qstr (1+ match))))
-            (funcall push (substring qstr (1+ match) end)
-                     (or end (length qstr)))))
+            (unless end
+              (setq end (length qstr))
+              (set-match-data (list match (length qstr))))
+            (funcall push (substring qstr (1+ match) end) end)))
+         ;; Ignore if at the end of string.
          (t nil)))
        (t (error "Unexpected case in shell--unquote&requote-argument!")))
       (setq qpos (match-end 0)))