damage: Validate source pictures bound to windows before unwrapping

The lower layers also do this, but no damage may be reported there,
since we unwrap before calling down.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99220Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 38696ea5)

configure.ac

@@ -1844,7 +1844,7 @@ if test "x$XNEST" = xyes; then
 	if test "x$have_xnest" = xno; then
 		AC_MSG_ERROR([Xnest build explicitly requested, but required modules not found.])
 	fi
-	XNEST_LIBS="$FB_LIB $FIXES_LIB $MI_LIB $XEXT_LIB $DBE_LIB $RECORD_LIB $GLX_LIBS $RANDR_LIB $RENDER_LIB $DAMAGE_LIB  $DRI3_LIB $PRESENT_LIB $MIEXT_SYNC_LIB $MIEXT_DAMAGE_LIB $MIEXT_SHADOW_LIB $XI_LIB $XKB_LIB $XKB_STUB_LIB $COMPOSITE_LIB $MAIN_LIB $DIX_LIB $OS_LIB"
+	XNEST_LIBS="$FB_LIB $FIXES_LIB $MI_LIB $XEXT_LIB $DBE_LIB $RECORD_LIB $GLX_LIBS $RANDR_LIB $DAMAGE_LIB  $DRI3_LIB $PRESENT_LIB $MIEXT_SYNC_LIB $MIEXT_DAMAGE_LIB $RENDER_LIB $MIEXT_SHADOW_LIB $XI_LIB $XKB_LIB $XKB_STUB_LIB $COMPOSITE_LIB $MAIN_LIB $DIX_LIB $OS_LIB"
 	XNEST_SYS_LIBS="$XNESTMODULES_LIBS $GLX_SYS_LIBS"
 	AC_SUBST([XNEST_LIBS])
 	AC_SUBST([XNEST_SYS_LIBS])

miext/damage/damage.c

@@ -34,6 +34,7 @@
 #include    <X11/fonts/fontstruct.h>
 #include    <X11/fonts/libxfont2.h>
 #include    "mi.h"
+#include    "mipict.h"
 #include    "regionstr.h"
 #include    "globals.h"
 #include    "gcstruct.h"
@@ -499,6 +500,15 @@ damageComposite(CARD8 op,
         if (BOX_NOT_EMPTY(box))
             damageDamageBox(pDst->pDrawable, &box, pDst->subWindowMode);
     }
+    /*
+     * Validating a source picture bound to a window may trigger other
+     * composite operations. Do it before unwrapping to make sure damage
+     * is reported correctly.
+     */
+    if (pSrc->pDrawable && WindowDrawable(pSrc->pDrawable->type))
+        miCompositeSourceValidate(pSrc);
+    if (pMask && pMask->pDrawable && WindowDrawable(pMask->pDrawable->type))
+        miCompositeSourceValidate(pMask);
     unwrap(pScrPriv, ps, Composite);
     (*ps->Composite) (op,
                       pSrc,