The following message is a courtesy copy of an article that has been posted to gmane.comp.lib.cairo as well.

On Sa, Okt 06, 2012 at 11:56:13 (CEST), Chris Wilson wrote:

On Sat, 6 Oct 2012 11:31:14 +0200, Andreas Radke <andyrtr@archlinux.org> wrote:

...

I've packaged the new release and it works well in ArchLinux with my local Awesome WM setup.

Remote connections using OpenNX are broken when used with Xfce. Xfce-panel and menu keep crashing instantly until I downgrade to 1.12.2 on the server.

There is not enough information here to begin to access the cause. A stack trace would be a good start.

It seems that cairo unconditionally assumes that the xserver does support the latest version of the Xrender extension:

http://cgit.freedesktop.org/cairo/tree/src/cairo-xlib-display.c?id=1.12.2#n2...

This assumption does not hold for many non-Xorg Xservers, including nxagent, which is used by NX and derivatives like OpenNX, FreeNX or X2Go:

http://code.x2go.org/gitweb?p=nx-libs.git;a=blob;f=nx-X11/include/extensions...

Note that the defines for Operators only available in version 0.11 in Xorg are *not* included:

/*

• Operators only available in version 0.11 */ #define PictOpBlendMinimum 0x30 #define PictOpMultiply 0x30 #define PictOpScreen 0x31 #define PictOpOverlay 0x32 #define PictOpDarken 0x33 #define PictOpLighten 0x34 #define PictOpColorDodge 0x35 #define PictOpColorBurn 0x36 #define PictOpHardLight 0x37 #define PictOpSoftLight 0x38 #define PictOpDifference 0x39 #define PictOpExclusion 0x3a #define PictOpHSLHue 0x3b #define PictOpHSLSaturation 0x3c #define PictOpHSLColor 0x3d #define PictOpHSLLuminosity 0x3e #define PictOpBlendMaximum 0x3e

Also, note that nxagent does not use pixman (which is the software implementation that Xorg uses nowadays), but the old, previous implementation of low-level pixel rendering, AFAIUI for example:

http://code.x2go.org/gitweb?p=nx-libs.git;a=blob;f=nx-X11/programs/Xserver/f...

I would assume that there are still a number of other non-Xorg X11 servers (most of them commercial) that do not support these operations.

Chris, is there any chance to fix/change cairo to work also without operators that are only available in version 0.11?

-- Gruesse/greetings, Reinhard Tartler, KeyID 945348A4