346751 - valgrind warning reading uninitialized mIgnoreClick in nsFormFillController::MouseClick

Status: RESOLVED WORKSFORME

(Toolkit :: Form Manager, defect)

Description

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

If I press enter to submit a form, I get a valgrind warning about uninitialized memory in nsFormFillController::MouseClick reading the mIgnoreClick variable.

Steps to reproduce:
 1. go to http://www.flickr.com/signin/flickr
 2. click in username box
 3. enter username (need not be real)
 4. hit tab
 5. enter password (need not be real)
 6. hit tab
 7. hit space
 8. hit tab
 9. hit enter to submit form

Actual results:
Valgrind warning

Expected results:
no valgrind warning

Observed in:
1.8 branch from a day or two ago, debug+opt, Linux

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Attachment: valgrind warning

Comment 2

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

(Note that I'm not sure that submitting with the mouse doesn't cause this problem, but that's my suspicion since there's a MouseDown handler.)

Comment 3

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

This is a one-line fix to get deterministic behavior.  The question is figuring out which behavior is right (PR_TRUE or PR_FALSE).

Comment 4

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

A quick glance says initializing to false is the right thing to do, although I'm not sure this code was designed for MouseClick to be called from keyboard events, and I'm not sure it really makes sense.

Comment 5

[Brian Ryner (not reading)]

It wasn't really designed for that, you'll see that it returns early if it fails to QI to MouseEvent, it just happens to check the uninitialized mIgnoreClick first.

Comment 6

[Justin Dolske [:Dolske]]

I think this code has since gone away... The MouseClick() method in FormFillController is just a 1-line "return PR_TRUE" now, and there's no mIgnoreMouseClick member either.