408893 - Glitch in GTK Tab borders using Personas

Status: NEW

(Core :: Widget: Gtk, defect, P5)

Description

[Daniel Holbert [:dholbert]]

With the "Personas" extention enabled, I'm still seeing tab-border glitches that are similar to bug 405670 (/ bug 404816), even though those bugs were fixed.

I'm guessing this is because Personas slightly changes the sizes of tabs and toolbars, and thereby puts us in a situation where a previously-hidden rounding error can now show itself.

Steps to reproduce:
   0. Install Personas, and select the "Developer Kit" persona (in "Most Popular" category)
   1. Open exactly three tabs in a Firefox window.  Select the third tab.
   2. Make the Firefox window pretty skinny
   3. Hit Alt-F8, to initiate a resize of the window.
   4. Repeatedly press right-arrow key, watching the left edge of the third tab.
     (if that doesn't reproduce bug, try slooowly resizing using mouse)

RESULTS:
 For some window-widths, a tiny bar at the left edge of the third tab turns completely transparent.  This happens for about every third window-width, as far as I can tell.

FURTHER EXPERIMENT:
 When you get to a window-width that shows the buggy results, you can see more buggy behavior with the transparent bar appearing / disappearing:

   4. Move mouse over third tab's title
      ** Results: transparent bar goes away (now it looks correct)
   5. Move mouse off straight upwards, rightwards, or downwards, off the title
       ** Results: still looks correct
   6. Move mouse over third tab's title again
   7. Move mouse directly to the left, over the second tab
       ** Results: transparent bar reappears
   8. Move mouse back to the right over third tab's title
       ** Results: transparent bar is still there.
    etc.

I'm not sure if this is a bug in Personas or in Widget:GTK, but I'm guessing it's Widget:GTK, just because I doubt that extentions / themes should be able to cause visual glitches like this.  (but I don't really know as I haven't hacked on extensions)

Comment 1

[Reed Loden [:reed]]

Any relation to bug 265698?

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: screenshot of problem

Comment 3

[Teune van Steeg]

(In reply to comment #1)
> Any relation to bug 265698?
> 

I'm sure this glitch will disappear when bug 265698 is fixed, because currently part of the tab is being cut off before drawing, which causes the left edge of one tab to touch the right edge of the other (or almost in this case). 
When bug 265698 is fixed the tabs will overlap each other so a small shift in position/size will not be noticeable.

This of course does not mean that there is no bug somewhere, look for instance at  attachment 271058 [details] which is an attachment from a windows only bug (bug 382458). 
Hovering those buttons reveals a bug which may be the same as what is described here.

Comment 4

[Julien "_FrnchFrgg_" RIVAUD]

Could you retest now that 265698 has landed ?

Comment 5

[Daniel Holbert [:dholbert]]

Can't right now, but I'll retest tomorrow using tomorrow morning's nightly.  Thanks for the fix!  Hope it works. :)

Comment 6

[Daniel Holbert [:dholbert]]

(In reply to comment #4)
> Could you retest now that 265698 has landed ?

I still see the bug, using 

Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9b3pre) Gecko/2007122204 Minefield/3.0b3pre

So, looks like the patch for bug 265698 didn't fix this.

Comment 7

[Daniel Holbert [:dholbert]]

FWIW, I still see this bug, though it's changed slightly:

If if I have 3 tabs open, and the third tab is selected, I *don't* see the glitch between tabs 2 and 3 anymore.

But if the *second* tab is selected, I still see the glitch between tabs 2 and 3.

Here are updated steps-to-reproduce (based on Comment 0):
   0. Install Personas, and select the "Developer Kit" persona (in "Most
Popular" category)
   1. Open exactly three tabs in a Firefox window.  Select the second tab.
   2. Make the Firefox window really skinny.
   3. Hit Alt-F8, to initiate a resize of the window.
   4. Repeatedly press right-arrow key, watching the right edge of the second tab.
     (if that doesn't reproduce bug, try slooowly resizing using mouse)

RESULTS:
 For some window-widths, the border almost entirely goes away between 2nd and 3rd tabs. This happens for about every third window-width, as far as I can tell.

Tested using Personas 0.9.2 and a debug build of Firefox checked out today (2008031317).

Comment 8

[Daniel Holbert [:dholbert]]

Attachment: screenshot: buggy behavior (look btwn 2nd and 3rd tabs)

Here's an updated screenshot of what I'm seeing.

Comment 9

[Daniel Holbert [:dholbert]]

Attachment: screenshot: good behavior (look btwn 2nd and 3rd tabs)

Here's a reference for the expected behavior. (compare against buggy attachment 309298 [details])

I got this simply by making the "buggy-behavior" Firefox window one "notch" wider. (via pressing alt-F8, rightarrow, rightarrow)

Comment 10

[Julien "_FrnchFrgg_" RIVAUD]

Attachment: The worst I get

That is the most buggy behaviour I can get here. It's difficult to trigger, but possible. I think it's the same bug.

Comment 11

[Myk Melez [:myk] [@mykmelez]]

I can reproduce this bug, and it's just as Daniel describes in comment 7.  Every third time I press the right-arrow key, part of the border between the second and third tabs disappears.

Comment 12

[Myk Melez [:myk] [@mykmelez]]

Attachment: testcase that demonstrates problem

Here's a minimal testcase that demonstrates the problem.  Note that the problem is not the background image personas adds, it's the opacity it sets: 0.8.  Without that, everything works fine.

Comment 13

[Firefox Bug Husbandry Bot]

https://bugzilla.mozilla.org/show_bug.cgi?id=1552613