glx: Add assert to check input to memcpy.

diff --git a/src/glx/glx_pbuffer.c b/src/glx/glx_pbuffer.c
index 4c122ba6ddc99c109b4414bfe0b468acecd1aaec..f635138d628714f7da9982bc57f1e05dcbddf3b4 100644 (file)
--- a/src/glx/glx_pbuffer.c
+++ b/src/glx/glx_pbuffer.c
@@ -379,6 +379,7 @@ CreateDrawable(Display * dpy, const __GLcontextModes * fbconfig,
    req->glxwindow = (GLXWindow) XAllocID(dpy);
    req->numAttribs = (CARD32) i;
 
+   assert(attrib_list);
    memcpy(data, attrib_list, 8 * i);
 
    UnlockDisplay(dpy);