Bug 83822 - device-offset test randomly fails because XCreatePixmap bits are undefined
Summary: device-offset test randomly fails because XCreatePixmap bits are undefined
Alias: None
Product: cairo
Classification: Unclassified
Component: xlib backend (show other bugs)
Version: unspecified
Hardware: Other All
: medium normal
Assignee: Chris Wilson
QA Contact: cairo-bugs mailing list
Depends on:
Reported: 2014-09-13 16:56 UTC by Massimo
Modified: 2018-08-25 13:33 UTC (History)
0 users

See Also:
i915 platform:
i915 features:

proposed patch (980 bytes, text/plain)
2014-09-13 16:56 UTC, Massimo

Description Massimo 2014-09-13 16:56:48 UTC
Created attachment 106221 [details]
proposed patch

while running

DISPLAY=:2 make test TARGETS=image,xlib

with Xvfb on display :2, to check a fix for bug #74779, occasionally
device-offset.xlib-render-0_0.rgb24 was reported PASS, even if the code
modified was not executed at all by that test.

The problem is that in that test (and few others) a temporary Pixmap is
created on the server and because render-0_0 does not have FillRectangles
an image surface is used to clear the Pixmap, but because the image surface
is already 'clear' it is left untouched and in _cairo_surface_unmap the 'clear'
image is not unmapped because untouched (image->base.serial == 0)


this means X's Pixmap is left in its original undefined state and only
occasionally it is clear.

I suggest to increment the serial member of the image_surface when the
'is_clear' state of the image_surface does not correspond to a clear
content of the corresponding xlib_surface, as in the attached patch.
Comment 1 GitLab Migration User 2018-08-25 13:33:40 UTC
-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

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