The -wm (when mapped) option for the BackingStore support has been
causing the server to dereference a NULL pointer.
This has probably been the case since backing store has been
implemented on top of Composite.
It looks like (some of?) Composite didn’t expect its WIndowPtr
argument to be the root window.
In Composite’s compCheckRedirect() function we now avoid calling
compAllocPixmap() and compFreePixmap() when the pWin pointer’s
parent member is NULL, as is it the case with a server’s root window.
This addresses:
https://bugs.freedesktop.org/show_bug.cgi?id=15878
The composite overlay window code had several misunderstandings of the
workings of the X server, in particular error handling paths would often
double-free objects. Clean all of this up by using resource destruction as
the sole mechanism for freeing resource-based objects.
- This allows some compositing managers to work, even after randr12 has changed the root window size.
- Thanks to ajax for figuring out the best place to put this.
- Example:
- xf86RandR12SetMode() calls EnableDisableFBAccess().
- That calls xf86SetRootClip() which in turn calls ResizeChildrenWinSize().
- The final step is the call to PositionWindow().
These hints allow an acceleration architecture to optimize allocation of certain
types of pixmaps, such as pixmaps that will serve as backing pixmaps for
redirected windows.
This was an attempt to avoid scratch gc creation and validation for paintwin
because that was expensive. This is not the case in current servers, and the
danger of failure to implement it correctly (as seen in all previous
implementations) is high enough to justify removing it. No performance
difference detected with x11perf -create -move -resize -circulate on Xvfb.
Leave the screen hooks for PaintWindow* in for now to avoid ABI change.
compNewPixmap copies bits from the parent window to the redirected child
pixmap to populate the pixmap with reasonable data. It cannot always use
CopyArea as that only works across matching depths. Use Composite when
the depths do not match.
over to new system.
Need to update documentation and address some remaining vestiges of
old system such as CursorRec structure, fb "offman" structure, and
FontRec privates.
Composite's automatic redirection is a more general mechanism than the
ad-hoc BS machinery, so it's much prettier to implement the one in terms
of the other. Composite now wraps ChangeWindowAttributes and activates
automatic redirection for windows with backing store requested. The old
backing store infrastructure is completely gutted: ABI-visible structures
retain the function pointers, but they never get called, and all the
open-coded conditionals throughout the DIX layer to implement BS are gone.
Note that this is still not a strictly complete implementation of backing
store, since Composite will throw the bits away on unmap and therefore
WhenMapped and Always hints are equivalent.
Besides being slightly simpler to read, it's now trivial to add a depth-16
visual to a depth-24 screen just by adding a line for it in the alternate
visual list. Visuals for indexed depths are slightly tricky still.
Installed protocol header version may be newer than the server code base.
Use internal version number for Composite extension to make sure the server
doesn't advertise capabilities it doesn't support.
This patch changes the semantics of manual redirect windows so that they no
longer affect the clip list of their parent. Doing this means the parent can
draw to the area covered by the child without using IncludeInferiors. More
importantly, this also means that the parent receives expose events when
that region is damaged by other actions.
Get rid of almost all uses of these definitions. They're still defined for
delinquent out-of-tree drivers, and also for the Mesa build. As well as
for miinitext.c. But largely gone.
Add new functions to enable and disable events on Map and Unmap.
Use them here to make sure Composite redirect doesn't cause Map/UnmapNotify
events that would confuse window managers.
Add XSERV_t, TRANS_SERVER, TRANS_REOPEN to quash warnings.
Add #include <dix-config.h> or <xorg-config.h>, as appropriate, to all
source files in the xserver/xorg tree, predicated on defines of
HAVE_{DIX,XORG}_CONFIG_H. Change all Xfont includes to
<X11/fonts/foo.h>.
