76033 - mozilla crashes on startup if using Qt-libs

Status: RESOLVED DUPLICATE of bug 78939

(Core :: XUL, defect)

Description

[brade]

I'm using the following configure line:

./configure --with-x --enable-toolkit=qt --with-qt --with-qtdir=/opt/qt-copy 
--disable-mailnews --enable-debug --disable-cpp-rtti --disable-cpp-exceptions 
--disable-tests

On startup of mozilla I get the following crash:

/mnt/Downloads/mozilla/dist/bin # ./mozilla
./run-mozilla.sh ./mozilla-bin
MOZILLA_FIVE_HOME=/mnt/Downloads/mozilla/dist/bin
  LD_LIBRARY_PATH=/mnt/Downloads/mozilla/dist/bin:/opt/qt-copy/lib
     
LIBRARY_PATH=/mnt/Downloads/mozilla/dist/bin:/mnt/Downloads/mozilla/dist/bin/components:/opt/qt-copy/lib
       SHLIB_PATH=/mnt/Downloads/mozilla/dist/bin
          LIBPATH=/mnt/Downloads/mozilla/dist/bin
       ADDON_PATH=/mnt/Downloads/mozilla/dist/bin
      MOZ_PROGRAM=./mozilla-bin
      MOZ_TOOLKIT=
        moz_debug=0
     moz_debugger=
Type Manifest File: /mnt/Downloads/mozilla/dist/bin/components/xpti.dat
nsNativeComponentLoader: autoregistering begins.
nsNativeComponentLoader: autoregistering succeeded
nNCL: registering deferred (0)
Initialized app shell component {18c2f989-b09f-11d2-bcde-00805f0e1353}, 
rv=0x00000000
GFX: dpi=97 t2p=0.0666667 p2t=15 depth=24
WEBSHELL+ = 1
nsPluginHostImpl ctor
********** Got plugins path: /mnt/Downloads/mozilla/dist/bin/plugins
WARNING: CSSLoaderImpl::LoadAgentSheet: Load of URL 
'file:///root/.mozilla/default/e4jpmpcd.slt/chrome/userChrome.css' failed.  
Error code: 18, file nsCSSLoader.cpp, line 1534
WARNING: CSSLoaderImpl::LoadAgentSheet: Load of URL 
'file:///root/.mozilla/default/e4jpmpcd.slt/chrome/userContent.css' failed.  
Error code: 18, file nsCSSLoader.cpp, line 1534
WEBSHELL+ = 2
Enabling Quirk StyleSheet
Note: verifyreflow is disabled
Style Data Sharing is Enabled :)
Note: styleverifytree is disabled
Note: frameverifytree is disabled
###!!! ASSERTION: You can't dereference a NULL nsCOMPtr with operator->().: 
'mRawPtr != 0', file ../../dist/include/nsCOMPtr.h, line 648
###!!! Break: at file ../../dist/include/nsCOMPtr.h, line 648
/mnt/Downloads/mozilla/dist/bin/run-mozilla.sh: line 72:  8395 
Speicherzugriffsfehler  $prog ${1+"$@"}

(Speicherzugriffsfehler == segmentation fault)

If I leave out the --enable-toolkit=qt --with-qt --with-qtdir=/opt/qt-copy 
everything is fine.

My system:
  SuSE Linux 7.0
  glibc-2.1.3
  gcc-2.95.3 (self-compiled)
  qt-2.3.0 (self-compiled with -xft)
  XFree86 4 cvs, with freetype2 and RENDER extension
  kernel 2.2.18

Hope this helps,
  Michael

Comment 1

[timeless]

-with-x ? is that right?

Comment 2

[John Griggs]

First of all, the options for building Qt Mozilla are:

--without-gtk 
 (seems to be required to completely turn off Gtk in the build)

--with-qt
--enable-toolkit=qt
 (turns on Qt build)

--disable-tests
 (Qt Mozilla does not include nsButton, etc. required for the test programs)

--with-qtdir=<path_to_qtdir>
 (Only required if Qt is not in the search path for the compiler and linker)

I have been waiting for approval on the wording of an announcement document that
will detail all of this.  I hope to post it to the relevant newsgroups and
mailing lists later today...

Secondly, I believe this crash is fixed by the patch from Bugzilla #75728
(http://bugzilla.mozilla.org/show_bug.cgi?id=75728).  This patch was checked in
to CVS Friday.  Can you re-test?

Comment 3

[Peter Trudelle]

->johng

Comment 4

[Keyser Sose]

Adding keywords ;)

Comment 5

[Matthias Versen [:Matti]]

Reporter: can you try it again with a new build ?
This should be fixed now.

Comment 6

[brade]

------- Additional Comments From [e-mail]  2001-05-12 09:38 -------
Reporter: can you try it again with a new build ?
This should be fixed now.

Hmm, yes and no. With 'export QT_XFT=0' (i.e. no antialiasing) it doesn't 
crash (and it never did ;-). But with QT_XFT=1 mozilla still crashes:

Note: verifyreflow is disabled
Note: styleverifytree is disabled
Note: frameverifytree is disabled
###!!! ASSERTION: You can't dereference a NULL nsCOMPtr with 
operator->().: 'mRawPtr != 0', file ../../../../dist/include/nsCOMPtr.h, 
line 649
###!!! Break: at file ../../../../dist/include/nsCOMPtr.h, line 649
/mnt/Downloads/mozilla/dist/bin/run-mozilla.sh: line 72: 24778 
Speicherzugriffsfehler  $prog ${1+"$@"}

Additionally I just noticed while testing that mozilla is *much* slower 
(especially scrolling a page) if it's using Qt (ok, I enabled debugging 
symbols in Qt and mozilla, but I doubt this is the reason...)

Ciao,
  Michael

Comment 7

[John Griggs]

This crash is due to a bug in Qt v2.3.0's support for anti-aliased fonts in
X11.  Qt Mozilla uses QFontDatabase to iterate through the system fonts and
implement the CSS 2 font selection alogirthm on top of the Qt mechanisms but,
with anti-aliased fonts in Qt 2.3, QFontDatabase reports no scaleable fonts or
valid sizes for any fonts on the system, so Mozilla fails to load any fonts. 
The crash occurs when nsGfxScrollFrame access a member of nsFontMetrics through
an invalid nsCOMPtr that is the result of a failed font load operation.  The
only known workaround is to turn off anti-aliased fonts (by setting QT_XFT=0 in
the environment).

Since this is a bug inside Qt itself, the chances of working around it in
Mozilla are small.  Hopefully, this will be fixed in Qt 3.0.  I will look into
this further when I get a chance to update one of my test machines to use
anti-aliased fonts.

As for speed, I haven't done a lot of work on performance tuning yet - I've been
concentrating on simply getting things working.  So there are almost certainly
places where the code could be faster.  BTW, there is a noticeable difference in
performance between Mozilla with debugging turned on and a build without
debugging and -O2 optimization - especially on slower machines or ones with less
memory... 

Comment 8

[John Griggs]

Added my home email as a CC, since I won't be at Corel after today...

Comment 9

[John Griggs]

I think this issue is addressed by the latest patch for nsFontMetricsQT.cpp in
Bugzilla #78939 (http://bugzilla.mozilla.org/show_bug.cgi?id=78939).  The
patches from #78939 add unicode font support, update the list of supported
charsets (based on the Gtk code) and works around a bug in Qt v2.3.0 support for
anti-aliased fonts.  This bug should be retested once #78939 is committed, so
I'm adding a dependancy.  TrollTech has also promised to fix the underlying bug
in v2.3.1 and v3.x of their library.

Comment 10

[baeda]

*** Bug 95900 has been marked as a duplicate of this bug. ***

Comment 11

[John C. Griggs]

I think this should be closed.  The work around for anti-aliased fonts in Qt has 
been in CVS for some time now...

Comment 12

[Christopher Aillon (sabbatical, not receiving bugmail)]

Resolve if you want.  relnote maybe?  "Linux - Building with qt requires qt
versions >= 2.3.1 (Bug 76033)"

cls: I know that qt is not officially supported, but should the build
configurator check this and fail if an older qt is installed?  We don't want
people thinking this is our problem...

Comment 13

[cls]

No, we don't want to do that.  Qt-2.2.4 works just fine and I see any reason to
force people to upgrade unnecessarily (especially if we already have the
workaround in).

Comment 14

[John C. Griggs]

> Resolve if you want.  

For some reason, Bugzilla does not give me this option.  All I get is "Leave as 
New".  I either need someone to change my permissions on this Bug or mark it as 
resolved on my behalf...

>relnote maybe?  "Linux - Building with qt requires qt
>versions >= 2.3.1 (Bug 76033)"

This is not true.  Qt Mozilla should build with any Qt 2.2.x or newer.  It is 
the work around for anti-aliased font support that is specific to Qt 2.3.x and 
the work around already takes this into account.

>cls: I know that qt is not officially supported, but should the build
>configurator check this and fail if an older qt is installed?  We don't want
>people thinking this is our problem...

There is already a check in the build configurator for this (Qt version >= 
2.2.0).

I'm positive that this bug was dealt with, in its entirety, some time ago.  I 
thought I had closed all of these (the problem with AA fonts was reported in 
several different Bugzilla tickets).

Comment 15

[John C. Griggs]

This bug was fixed in Bugzilla #78939.  Marking as a duplicate.

*** This bug has been marked as a duplicate of 78939 ***