winex11.drv: Load the XComposite extension when available.
diff --git a/configure.ac b/configure.ac
index b951604..00c5bfe 100644
--- a/configure.ac
+++ b/configure.ac
@@ -518,6 +518,7 @@
                       X11/extensions/shape.h \
                       X11/extensions/XInput.h \
                       X11/extensions/XShm.h \
+                      X11/extensions/Xcomposite.h \
                       X11/extensions/Xinerama.h \
                       X11/extensions/Xrandr.h \
                       X11/extensions/Xrender.h \
@@ -614,6 +615,14 @@
         WINE_NOTICE_IF([test "x$ac_cv_lib_soname_Xinerama" = "x"],[Xinerama development files not found.
 Wine will be built without Xinerama support. (winex11.drv)])
 
+        dnl *** Check for X Composite extension
+        if test "$ac_cv_header_X11_extensions_Xcomposite_h" = "yes"
+        then
+            WINE_CHECK_SONAME(Xcomposite,XCompositeRedirectWindow,,,[$X_LIBS -lXext -lX11 $X_EXTRA_LIBS])
+        fi
+        WINE_NOTICE_IF([test "x$ac_cv_lib_soname_Xcomposite" = "x"],[XComposite development files not found.
+Wine will be built without XComposite support. (winex11.drv)])
+
     dnl *** End of X11/Xlib.h check
 
     dnl Check for the presence of OpenGL