added sanity check

diff --git a/lib/devices/ops.c b/lib/devices/ops.c
index 8342930..cb0c6f1 100644 (file)
--- a/lib/devices/ops.c
+++ b/lib/devices/ops.c
@@ -160,7 +160,9 @@ void ops_endpage(struct _gfxdevice*dev)
 
 gfxresult_t* ops_finish(struct _gfxdevice*dev)
 {
-    free(dev->internal);dev->internal = 0;
+    if(dev->internal) 
+       free(dev->internal);
+    dev->internal = 0;
     return 0;
 }