147704 - Display problem: missing font rendering, without Xft

Status: RESOLVED WORKSFORME

(Core Graveyard :: GFX: Gtk, defect)

Description

[Vincent Lefevre]

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux ppc; en-US; rv:1.0.0+) Gecko/20020524
BuildID:    2002052323

The page at the given URL doesn't display correctly: random blank horizontal
spaces appear (i.e. some parts of the page are not visible).

Reproducible: Always
Steps to Reproduce:
1. Open the URL.
2. See what is displayed.
3. You may also scroll.

Actual Results:  Random parts (sometimes a thin horizontal line), mainly math
formulas but also normal text, are not visible. This changes when scrolling. The
page layout seems to be OK, though.

Expected Results:  The document should be correctly displayed.

Comment 1

[Vincent Lefevre]

Same problem with Mozilla 1.0.

Comment 2

[rbs]

-> changing component to MathML (otherwise it doesn't get appropriate 
visibility...)

Got a screenshot?

Comment 3

[Vincent Lefevre]

After some tests, the problem seems to only occur when using a VNC server.
Finally, perhaps a bug in the VNC implementation?

Comment 4

[Vincent Lefevre]

I've put some snapshots here:

  http://www.vinc17.org/download/mathml1.png
  http://www.vinc17.org/download/mathml2.png
  http://www.vinc17.org/download/mathml3.png
  http://www.vinc17.org/download/mathml4.png

Comment 5

[Vincent Lefevre]

Attachment: Output of xdpyinfo

Here's a new snapshot:

  http://www.vinc17.org/download/mathml5.png

You can see that this is a redraw problem, but I don't know why it occurs on
this page only. If I iconize the window and reopen it, nothing is redrawn in
the part of the window corresponding to the document, i.e. I can see what's
behind just like if the background were transparent.

When launching ksnapshot, I got the message:

Xlib:  extension "RENDER" missing on display "ay:1.0".

but nothing else wrong. I've attached the output of xdpyinfo in case Mozilla
requires specific extensions.

Comment 6

[Alexander Opitz]

@reporter

Does it happens with newer builds?

You don't need the RENDER extension of your X ... but you can enable it for KDE
for faster output :-) See your XFree86.conf

Comment 7

[Vincent Lefevre]

I now use a Xft-enabled version and I no longer see any blank spaces problem.
The characters (when they exist) are incorrectly positioned, but I suppose that
this comes from bug 128153.

Comment 8

[Alexander Opitz]

So ok ... discussion go over to bug 128153 and I'll close this bug as Invalide.

Comment 9

[Vincent Lefevre]

It wasn't invalid. There are two display problems: one probably due to bug
128153, and one that occurred in old versions of Mozilla (compiled without Xft
support, but I now always compile with Xft support). Contrary to the former
problem, the latter one (this bug) depended on how the page was redrawn (e.g.
when scrolling).

Comment 10

[Vincent Lefevre]

I've recompiled Mozilla (latest nightly source + make -f client.mk) without Xft
support. The bug is still there. So, I reopen the bug.

Comment 11

[Christian :Biesinger (don't email me, ping me on IRC)]

hmm, maybe duplicate of bug 190278? (that bug is not really limited to hebrew,
contrary to what the summary says)

Comment 12

[Alexander Opitz]

Vincent, do you use trunk or 1.4 branch?
Is it a problem with Xft on ppc or also with Xft on x86?

Comment 13

[Vincent Lefevre]

No, it is not a dup of bug 190278 (which is related to Xft): I get the problem
when I compile Mozilla *without* Xft support. So, it is *not* a problem with Xft
in my case.

I always use the trunk.

Comment 14

[Vincent Lefevre]

Now that I have a working configuration for Xft-enabled Mozilla, I can confirm
that this bug doesn't occur *with* Xft.

Comment 15

[rbs]

Over to Gfx:Gtk, then.

Comment 16

[Mats Palmgren (inactive)]

gfx/src/gtk/ has been removed on trunk.
Does this bug occur in a recent (cairo) trunk build?

Comment 17

[Vincent Lefevre]

There's still some blank (I get "a  η  b" instead of "a ≤ η ≤ b") and incorrect font display, but I don't know if this is the same bug. Tried with Mozilla/5.0 (X11; U; Linux ppc; en-US; rv:1.8.1.4) Gecko/20070508 Iceweasel/2.0.0.4 (Debian-2.0.0.4-0etch1). I'm going to attach a snapshot.

Comment 18

[Vincent Lefevre]

Attachment: Snapshot using Firefox 2.0.0.4 on Debian/ppc

Comment 19

[Mats Palmgren (inactive)]

There are some troubleshooting tips and fonts at this URL that might help:
http://www.mozilla.org/projects/mathml/fonts/

Comment 20

[Vincent Lefevre]

(In reply to comment #19)
> There are some troubleshooting tips and fonts at this URL that might help:
> http://www.mozilla.org/projects/mathml/fonts/

I did the font installation a long time ago (and I don't get the warning box saying that some fonts for MathML are missing).

Also note that this is a build *with* Xft (about:buildconfig says that --enable-xft is provided), though the problem occurred without Xft. But I no longer use builds without Xft. The problem I mentioned in comment #17 may be another (new) bug.

Comment 21

[Zack Weinberg (:zwol)]

As far as I can tell, both the --enable-xft and --disable-xft modes have been completely superseded by cairo and freetype in the current source base.  The browser I'm typing this in (distro build of Firefox 8) renders the test page correctly.  Closing.