12645 - [Dogfood] Using scroll bar in Messenger causes crash - folder pane

Status: VERIFIED FIXED

(MailNews Core :: Backend, defect, P1)

Description

[esther]

Using 1999082617 M10 build on Win98, Scroll bar is acting up and usage causes a
crash.  As stated in bug 12140 the scroll bar will flip back and forth from
right to left side of pane when you have moved the slider to the bottom.  When
this happens, if you click on the arrows at the top and bottom of the scroll bar
when it's on the left side, it move back to the right side.  Continuing this
will eventually lead to a crash.  I have 3 talkback report, but the server seems
to be down and not receiving them at this time.  When I get them I will post the
incident number and stack.  Still need to check linux and mac.

1. Launch Messenger (using apprunner -mail) (have at least 3 accounts so you can
fill the Folder pane)
2. Expand folders in the folder pane to force the scroll bar to display
3. Keep  expanding folders, then click on the down arrow of the scroll bar so
the scroll bar moves to the left side of the pane.
4. Click on the scroll bar on the left side (continuously until it moves back to
the right side).
5. Continue steps 2,3,4 randomly until you crash (usually withing 2 minutes).

Comment 1

[esther]

The last linux build on the 26th crashes when mousing over the scroll bar (which
means is it is the build that has bug 12534) and the 27 build doesn't launch,
so I will have to wait for another build to test linux.   Mac build 999082614
displays the same scroll bar flakiness and takes more to crash, but it does
crash.  A talkback incident will be noted when it is received.   Changing to
All.

Comment 2

[esther]

I took the latest linux build dated 1999082906 M10 it crashes too (note: the
linux build has a date later than the timestamp on this comment, the directory
and date are wrong I took the build at 2:00 8/27)

Comment 3

[esther]

Another update... took the newest 8/27 builds on win98 (1999082712M10), linux
(1999082705M10) and mac (1999082712M10) this still happens.  Talkback still
isn't receiving incidents so I will sent one when I get it in.

Comment 4

[David Hyatt]

Fixed.  Note that there still is a scrollbar crash (caused by scrolling up
rapidly), but this crash is different and has been fixed.

Comment 5

[esther]

Using build 19990914 on win98 & NT4.0, and linux (mac not tested yet) this still
crashes.  It doesn't crash when you scroll by dragging the bar up and down, but
when you click the down or up arrows for the scroll bar it crashes.  Reopening
this bug

Comment 6

[lchiang]

M10 has passed - pls assign a new target milestone. Thanks.

Comment 7

[Phil Peterson]

hyatt or trudelle, is the remaining part of this bug an issue for evaughan?

Comment 8

[Peter Trudelle]

setting p1 for m11

Comment 9

[lchiang]

changing dependency bug to the beta tracking bug

Comment 10

[David Hyatt]

My hands have deteriorated to the point where I can no longer type.  I need
help.  If you think you can fix this bug on your own, please take it away from
me.  If you'd like to volunteer to be my hands for a specific bug, then I'll be
happy to come up to your cube and sit with you and fix the bug (assuming you
have the patience for that).

Comment 11

[Phil Peterson]

Dave, being a manager, I have no important work to do, so I volunteer to be your
hands. My tip build is about an hour from being done.

Comment 12

[scottputterman]

I will look into this one.  I will probably be by for some pointers.

Comment 13

[David :Bienvenu]

One cause of this crash was a dereference of a null pointer in
layout\base\src\nsGenericElement.cpp in the following code:

nsGenericElement::Release()
{
  nsrefcnt rc=0;
  NS_ASSERTION(mContent, "nsGenericElement: Nothing to release!");
  if (mContent)
    NS_RELEASE2(mContent, rc);
  return rc;

AlecF fixed this code to check mContent before releasing - I wonder if that's
what people were seeing re a crash scrolling.

Comment 14

[scottputterman]

Yeah, probably.  It's asserting now which is much better than crashing but still
pretty annoying for a debug build.

Comment 15

[Alec Flett]

so the problem still exists.
Strangely, I don't see this assertion anymore on Unix.

Comment 16

[David :Bienvenu]

It still happens in the folder pane on windows - it doesn't happen in the thread
pane, at least for me.

Comment 17

[scottputterman]

I checked in a fix for the assertion.

Comment 18

[fenella]

Linux (1999-10-20-11 M11) commercial
Win NT (1999-10-20-11 M11) commercial
Mac (1999-10-20-11 M11) commercial
I do not see the scroll bar move to left and to right any more.  And I do not
see any crash using the scenario as described. However I am seeing Linux crashes
when I drag the scroll bar up and down for a period of time. Will write another
bug for that parity bug.

Comment 19

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/70cfa3f6b9f0
[components] Close https://github.com/mozilla-mobile/android-components/issues/12645: Add sync engine aware debouncing
https://hg.mozilla.org/integration/autoland/rev/4e9060d2d539
[fenix] Closes https://github.com/mozilla-mobile/fenix/issues/12645: Re-enable mediaSystemNotificationInPrivateModeTest