Loaded autopair.el causes errors in pre-command-hook

[Urs Fleisch]

Reproduction:

Use the following emacs initialization file (e.g. ~/.emacs.d/init.el):
---
(delete-selection-mode t)
(setq py-install-directory "~/.emacs.d/vendor/components-python-mode")
(add-to-list 'load-path py-install-directory)
(autoload 'python-mode "python-components-mode" "Python editing mode." t)
---

Start Emacs, open a text file and a Python file, switch between the two files using the "Buffers" menu.
Errors occur, as can be seen in the "*Messages*" buffer:

Error in pre-command-hook: (wrong-type-argument symbolp (lambda nil (interactive) (switch-to-buffer example.txt)))
Error in pre-command-hook: (wrong-type-argument symbolp (lambda nil (interactive) (switch-to-buffer example.py)))

Reason for errors:

autopair.el as delivered with wraps an advice around delete-selection-pre-hook, which calls autopair-should-autowrap(), which calls (symbol-name this-command). However, in the described case, this-command is not a symbol, but (lambda nil (interactive) (switch-to-buffer #<buffer example.txt>)).

Fix:

Replaces autopair-should-autowrap with the current version in Git, which has this bug fixed.

---
=== modified file 'autopair/autopair.el'
--- autopair/autopair.el 2012-07-16 07:16:17 +0000
+++ autopair/autopair.el 2012-08-12 10:15:43 +0000
@@ -1171,11 +1171,11 @@
 (put 'autopair-newline 'delete-selection t)

 (defun autopair-should-autowrap ()
- (let ((name (symbol-name this-command)))
- (and autopair-mode
- (not (eq this-command 'autopair-backspace))
- (string-match "^autopair" (symbol-name this-command))
- (autopair-calculate-wrap-action))))
+ (and autopair-mode
+ (not (eq this-command 'autopair-backspace))
+ (symbolp this-command)
+ (string-match "^autopair" (symbol-name this-command))
+ (autopair-calculate-wrap-action)))

 (defadvice cua--pre-command-handler-1 (around autopair-override activate)
   "Don't actually do anything if autopair is about to autowrap. "

---

This patch can also be found in my branch lp:~ufleisch/python-mode/improve-completion.