Patch to Fix x2goagent / nxagent With New LibCairo

10 May 2012


      I don't know what the current patch status is for fixing nxagent with the
new libcairo (1.12.1+ I believe), but eventually I got tired of waiting and
created my own patches for nxagent/x2goagent.
Most of the fixes were required because the render extension now allows
(and libcairo uses) null source drawables (for gradients etc), null masks
and null mask drawables.
This change creates a bit of a logic mess in the code.   Previous patches
to the code tried to account for all of the possibilities, but fell a
little short.
Consider this an alpha-quality patch.  I've only tested it in KDE while
running GTK applications.   All my favorite GTK apps like Firefox, Emacs,
rox-filer and all my other GTK apps that were broken are now working just
fine.  (Though I'm getting only the standard GTK look and feel - don't know
if that's caused by anything I've done.)
Could someone test this under Gnome?
Also, since I'm not primarily an X software engineer I'd like a specialist
to take a look at it.   The fix is a little crude.   I just attached to the
x2goagent process and fixed the lines that caused segfaults.   (About 10 of
them).
I also rewrote one of the macros in Pixels.h into a local subroutine in
Render.c.  It had a bug in it and complex macro bugs are a PITA to debug in
gdb (or anything else really).   The macro is only used in one place and
although the code in the macro is called pretty often, it's very likely
that the compiler would inline it anyway.  The rewrite increases
readability by a large factor.
A better patch could be created by someone that understands nxagent and X
much better.   The render extension code receives render ops from X client
programs.  The render ops can contain any combination of picture source,
picture destination and picture mask.  It's apparently legal to send render
ops with combinations of null picture source drawables, picture masks and
picture mask drawables.   A better way to patch this would be to simply
perform a return on all the illegal combinations of null parameters for the
render ops.  That way you wouldn't have to keep re-checking the parameter
values.
So anyway, here it is.  I appreciate it if someone out there would test it
and let me know.   Also if anyone knows of the X docs which discuss null
picture sources and masks in the render extension I'd be glad to create a
cleaner patch that conforms to the stands.
Let me know.
eris0xff
*** x2go/nx-libs-3.5.0.12/nx-X11/programs/Xserver/hw/nxagent/Render.c
2012-03-07 14:04:02.000000000 -0700
x2go-new/nx-libs-3.5.0.12/nx-X11/programs/Xserver/hw/nxagent/Render.c
2012-05-10 11:09:39.631786853 -0600

*** 995,1000 ****
--- 995,1030 ----
#endif
}


int nxagentShouldDeferComposite(PicturePtr pSrc, PicturePtr pMask,
PicturePtr pDst)
{

int drawableDst;
int linkDeferred;
int unSyncedSrcMask;

drawableDst      =  ( nxagentRenderVersionMajor == 0 &&

                      nxagentRenderVersionMinor == 8 &&

                  (pDst) -> pDrawable -> type == DRAWABLE_PIXMAP

                        );


linkDeferred     =  ( nxagentOption(DeferLevel) >= 2
&&
                          nxagentOption(LinkType) &lt; LINK_TYPE_ADSL

                        );


unSyncedSrcMask  =  ( nxagentOption(DeferLevel) == 1 &&

                          (pDst) -> pDrawable -> type ==
DRAWABLE_PIXMAP &&
                          (

               (pSrc -> pDrawable && (nxagentDrawableStatus(pSrc ->
pDrawable) == NotSynchronized)) ||
                       ((pMask) && pMask -> pDrawable &&
(nxagentDrawableStatus((pMask) -> pDrawable) == NotSynchronized))
              )

            );


return drawableDst || linkDeferred || unSyncedSrcMask;

}

void nxagentComposite(CARD8 op, PicturePtr pSrc, PicturePtr pMask,
PicturePtr pDst,
INT16 xSrc, INT16 ySrc, INT16 xMask, INT16
yMask, INT16 xDst,
INT16 yDst, CARD16 width, CARD16 height)


*** 1036,1043 ****
}
#endif
!
!   if (NXAGENT_SHOULD_DEFER_COMPOSITE(pSrc, pMask, pDst))
{
pDstRegion = nxagentCreateRegion(pDst -> pDrawable, NULL, xDst, yDst,
width, height);
--- 1066,1073 ----
}
#endif
!   /* if (NXAGENT_SHOULD_DEFER_COMPOSITE(pSrc, pMask, pDst)) */
!   if (nxagentShouldDeferComposite(pSrc, pMask, pDst))
{
pDstRegion = nxagentCreateRegion(pDst -> pDrawable, NULL, xDst, yDst,
width, height);

*** 1095,1101 ****
}
}
!   if (pMask != NULL && pMask -> pDrawable != pSrc -> pDrawable &&
pMask -> pDrawable != pDst -> pDrawable)
{
nxagentSynchronizeShmPixmap(pMask -> pDrawable, xMask, yMask, width,
height);
--- 1125,1132 ----
}
}
!   if ((pMask) && (pMask->pDrawable) &&
!           pMask -> pDrawable != pSrc -> pDrawable &&
pMask -> pDrawable != pDst -> pDrawable)
{
nxagentSynchronizeShmPixmap(pMask -> pDrawable, xMask, yMask, width,
height);

*** 1259,1265 ****
* on the real X server.
*/
!   if (nxagentDrawableStatus(pSrc -> pDrawable) == NotSynchronized)
{
#ifdef TEST
fprintf(stderr, "nxagentGlyphs: Synchronizing source [%s] at [%p].\n",
--- 1290,1296 ----
* on the real X server.
*/
!   if (pSrc -> pDrawable && (nxagentDrawableStatus(pSrc -> pDrawable) ==
NotSynchronized))
{
#ifdef TEST
fprintf(stderr, "nxagentGlyphs: Synchronizing source [%s] at [%p].\n",

*** 1302,1315 ****
nxagentSynchronizeBox(pSrc -> pDrawable, &glyphBox, NEVER_BREAK);
}
!     if (pSrc -> pDrawable -> type == DRAWABLE_PIXMAP)
{
nxagentIncreasePixmapUsageCounter((PixmapPtr) pSrc -> pDrawable);
}
}
!   if (pSrc -> pDrawable != pDst -> pDrawable &&
!           nxagentDrawableStatus(pDst -> pDrawable) == NotSynchronized)
{
#ifdef TEST
fprintf(stderr, "nxagentGlyphs: Synchronizing destination [%s] at
[%p].\n",
--- 1333,1347 ----
nxagentSynchronizeBox(pSrc -> pDrawable, &glyphBox, NEVER_BREAK);
}
!     if (pSrc -> pDrawable && (pSrc -> pDrawable -> type ==
DRAWABLE_PIXMAP))
{
nxagentIncreasePixmapUsageCounter((PixmapPtr) pSrc -> pDrawable);
}
}
!
!   if (pSrc -> pDrawable && (pSrc -> pDrawable != pDst -> pDrawable &&
!           nxagentDrawableStatus(pDst -> pDrawable) == NotSynchronized))
{
#ifdef TEST
fprintf(stderr, "nxagentGlyphs: Synchronizing destination [%s] at
[%p].\n",

*** 1749,1755 ****
return;
}
!   if (nxagentDrawableStatus(pSrc -> pDrawable) == NotSynchronized)
{
#ifdef TEST
fprintf(stderr, "nxagentTrapezoids: Going to synchronize the source
drawable at [%p].\n",
--- 1781,1789 ----
return;
}
!   /* the following blocks need fixing to ignore null values of pDrawable
*/
!
!   if (pSrc -> pDrawable && (nxagentDrawableStatus(pSrc -> pDrawable) ==
NotSynchronized))
{
#ifdef TEST
fprintf(stderr, "nxagentTrapezoids: Going to synchronize the source
drawable at [%p].\n",

*** 1843,1849 ****
* operation like nxagentTrapezoids() does.
*/
!   if (nxagentDrawableStatus(pSrc -> pDrawable) == NotSynchronized)
{
#ifdef TEST
fprintf(stderr, "nxagentTriangles: Going to synchronize the source
drawable at [%p].\n",
--- 1877,1885 ----
* operation like nxagentTrapezoids() does.
*/
!
!
!   if (pSrc -> pDrawable && (nxagentDrawableStatus(pSrc -> pDrawable) ==
NotSynchronized))
{
#ifdef TEST
fprintf(stderr, "nxagentTriangles: Going to synchronize the source
drawable at [%p].\n",

*** 1920,1926 ****
* operation like nxagentTrapezoids() does.
*/
!   if (nxagentDrawableStatus(pSrc -> pDrawable) == NotSynchronized)
{
#ifdef TEST
fprintf(stderr, "nxagentTriStrip: Going to synchronize the source
drawable at [%p].\n",
--- 1956,1963 ----
* operation like nxagentTrapezoids() does.
*/
!
!   if (pSrc -> pDrawable && (nxagentDrawableStatus(pSrc -> pDrawable) ==
NotSynchronized))
{
#ifdef TEST
fprintf(stderr, "nxagentTriStrip: Going to synchronize the source
drawable at [%p].\n",

*** 1997,2003 ****
* operation like nxagentTrapezoids() does.
*/
!   if (nxagentDrawableStatus(pSrc -> pDrawable) == NotSynchronized)
{
#ifdef TEST
fprintf(stderr, "nxagentTriFan: Going to synchronize the source
drawable at [%p].\n",
--- 2034,2041 ----
* operation like nxagentTrapezoids() does.
*/
!
!   if (pSrc -> pDrawable && (nxagentDrawableStatus(pSrc -> pDrawable) ==
NotSynchronized))
{
#ifdef TEST
fprintf(stderr, "nxagentTriFan: Going to synchronize the source
drawable at [%p].\n",

*** x2go/nx-libs-3.5.0.12/nx-X11/programs/Xserver/hw/nxagent/Render.c 2012-03-07 14:04:02.000000000 -0700

*** x2go/nx-libs-3.5.0.12/nx-X11/programs/Xserver/hw/nxagent/Render.c 2012-03-07 14:04:02.000000000 -0700

* x2go/nx-libs-3.5.0.12/nx-X11/programs/Xserver/hw/nxagent/**Render.c 2012-03-07 14:04:02.000000000 -0700

* x2go/nx-libs-3.5.0.12/nx-X11/programs/Xserver/hw/nxagent/**Render.c 2012-03-07 14:04:02.000000000 -0700

Patch to Fix x2goagent / nxagent With New LibCairo

*** x2go/nx-libs-3.5.0.12/nx-X11/programs/Xserver/hw/nxagent/Render.c 2012-03-07 14:04:02.000000000 -0700

*** x2go/nx-libs-3.5.0.12/nx-X11/programs/Xserver/hw/nxagent/Render.c 2012-03-07 14:04:02.000000000 -0700

*** x2go/nx-libs-3.5.0.12/nx-X11/**programs/Xserver/hw/nxagent/**Render.c 2012-03-07 14:04:02.000000000 -0700

*** x2go/nx-libs-3.5.0.12/nx-X11/**programs/Xserver/hw/nxagent/**Render.c 2012-03-07 14:04:02.000000000 -0700

* x2go/nx-libs-3.5.0.12/nx-X11/programs/Xserver/hw/nxagent/**Render.c 2012-03-07 14:04:02.000000000 -0700

* x2go/nx-libs-3.5.0.12/nx-X11/programs/Xserver/hw/nxagent/**Render.c 2012-03-07 14:04:02.000000000 -0700