#3 python-mode loops on if/else

[Skip Montanaro]

(migrating from python project)

Original submission:

Here's how to reproduce. Create a .py file in XEmacs
containing this text:

x = (if 1: 2
____else: 3)

(except that the ____ really means four spaces).

Now position your cursor somewhere inside those 4
spaces, and hit TAB. XEmacs freezes until you hit
^G.

Followup comments:

Date: 2003-07-31 22:41
Sender: montanaro
Logged In: YES
user_id=44345

The code gets into an infloop in py-outdent-p. The
loop looks
odd to me:

(while (or (looking-at py-blank-or-comment-re)
(bobp))
(backward-to-indentation 1))

If you were at (bobp), why would you want to try to
move back
a line?

[Mark Byers]

Logged In: YES
user_id=1223583

I can confirm this bug.

The following two line file also causes an infinite loop:

a
else:

When the colon is typed, the inifinite loop is triggered.

I think the following change fixes the problem:

- (while (or (looking-at py-blank-or-comment-re)
- (bobp))
+ (while (and (looking-at py-blank-or-comment-re)
+ (not (bobp)))
(backward-to-indentation 1))

[Mark Byers]

Logged In: YES
user_id=1223583

Here is a patch file. I wasn't sure how to attach it as a
file, so here it is in plain text. It seems that the 'short
circuit infloop on illegal construct' line is no longer
needed so I have removed it.

--- python-mode/python-mode.el 2005-02-20 14:23:58.000000000
+0100
+++ python-mode/python-mode.el.new 2005-02-20
14:29:05.319602112 +0100
@@ -1239,13 +1239,11 @@
(save-excursion
(and (progn (back-to-indentation)
(looking-at py-outdent-re))
- ;; short circuit infloop on illegal construct
- (not (bobp))
(progn (forward-line -1)
(py-goto-initial-line)
(back-to-indentation)
- (while (or (looking-at py-blank-or-comment-re)
- (bobp))
+ (while (and (looking-at py-blank-or-comment-re)
+ (not (bobp)))
(backward-to-indentation 1))
(not (looking-at py-no-outdent-re)))
)))