[Xephyr] Fix #15839

Make sure the _XSERVER64 macro is not defined in Xlib client code.
That macro is meant to be define only on pure server code, when necessary.
(cherry picked from commit 5de1867fbb)

hw/kdrive/ephyr/XF86dri.c

@@ -45,6 +45,16 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #ifdef HAVE_CONFIG_H
 #include <kdrive-config.h>
 #endif
+/*
+ * including some server headers (like kdrive-config.h)
+ * might define the macro _XSERVER64
+ * on 64 bits machines. That macro must _NOT_ be defined for Xlib
+ * client code, otherwise bad things happen.
+ * So let's undef that macro if necessary.
+ */
+#ifdef _XSERVER64
+#undef _XSERVER64
+#endif
 
 #ifdef XEPHYR_DRI
 

hw/kdrive/ephyr/ephyrhostglx.c

@@ -31,6 +31,17 @@
 #include <kdrive-config.h>
 #endif
 
+/*
+ * including some server headers (like kdrive-config.h)
+ * might define the macro _XSERVER64
+ * on 64 bits machines. That macro must _NOT_ be defined for Xlib
+ * client code, otherwise bad things happen.
+ * So let's undef that macro if necessary.
+ */
+#ifdef _XSERVER64
+#undef _XSERVER64
+#endif
+
 #include <X11/Xlibint.h>
 #include <GL/glx.h>
 #include <GL/internal/glcore.h>

hw/kdrive/ephyr/ephyrhostvideo.c

@@ -28,6 +28,16 @@
 #ifdef HAVE_CONFIG_H
 #include <kdrive-config.h>
 #endif
+/*
+ * including some server headers (like kdrive-config.h)
+ * might define the macro _XSERVER64
+ * on 64 bits machines. That macro must _NOT_ be defined for Xlib
+ * client code, otherwise bad things happen.
+ * So let's undef that macro if necessary.
+ */
+#ifdef _XSERVER64
+#undef _XSERVER64
+#endif
 #include <X11/Xutil.h>
 #include <X11/Xlibint.h>
 #include <X11/extensions/Xvlib.h>

hw/kdrive/ephyr/hostx.c

@@ -27,6 +27,18 @@
 #include <kdrive-config.h>
 #endif
 
+/*
+ * including some server headers (like kdrive-config.h)
+ * might define the macro _XSERVER64
+ * on 64 bits machines. That macro must _NOT_ be defined for Xlib
+ * client code, otherwise bad things happen.
+ * So let's undef that macro if necessary.
+ */
+#ifdef _XSERVER64
+#undef _XSERVER64
+#endif
+
+
 #include "hostx.h"
 
 #include <stdlib.h>