608445 - Hang after key click on about:* pages

Status: VERIFIED FIXED

(Firefox for Android Graveyard :: General, defect)

Description

[Alon Zakai (:azakai)]

1. Start Fennec
2. Click inside the about:home page (or, about:memory, about:config, etc.).
3. Alt-tab to another application, then alt-tab back.

Result: Fennec is completely unresponsive, CPU is at 100%, Fennec does not repaint its window.

Breaking in a debugger at this point shows various stack traces - no obvious culprit here.

Seen on Linux desktop. (Not sure how to test this on a device - what is the equivalent of 'alt-tab'-ing away?)

Comment 1

[Naoki Hirata :nhirata (please use needinfo instead of cc)]

Note :
1) On Android : home button
2) On Maemo : hitting the icon in the upper left hand corner will get you out of the app while the app is still running in the background.

I noticed something similar while regressing bug 603680 on maemo.

Comment 2

[Alon Zakai (:azakai)]

Simpler steps:

1. Start Fennec
2. Click inside the about:home page (or, about:memory, about:config, etc.).
3. **Press a key (e.g. space)** - different from before

The hang begins when the key is clicked. Note, as mentioned above, that this does not occur if you do not click the mouse first in the page.

Comment 3

[Alon Zakai (:azakai)]

Attachment: patch

Bug was, that doing

  utils.sendKeyEvent(json.type, json.keyCode, json.charCode, modifiers);

will send a key event to the child. In the case of a local page, this leads to an infinite loop. Fix is to not send the unneeded key event if the page is local.

I don't think the change breaks anything - key presses still work on about:config, for example. Anything else to test?

Comment 4

[Matt Brubeck (:mbrubeck)]

Comment on attachment 487460 [details] [diff] [review]
patch

>+        if (!Util.isLocalScheme(content.document.URL))

I would use "if (Util.isParentProcess())" instead.

By the way, thank you so much for finding and fixing this!

Comment 5

[Alon Zakai (:azakai)]

Attachment: patch v2

Cool, made the patch do it that way.

Comment 6

[Alon Zakai (:azakai)]

http://hg.mozilla.org/mobile-browser/rev/dc75496e9e74

Comment 7

[Ayan Shah[:ashah]]

verified fixed on:

Mozilla/5.0(Android; Linux armv7l;rv2.0b8pre) Gecko/20101102 Firefox/4.0b8pre
Fennec/4.0b3pre

AND

Mozilla/5.0(Maemo; Linux armv7l;rv2.0b8pre) Gecko/20101102 Firefox/4.0b8pre
Fennec/4.0b3pre