check non-null before any use.

diff --git a/ext/gd/libgd/gd.c b/ext/gd/libgd/gd.c
index 7bc25e710f9eebfc4d32505c0a898bf67fc8c56b..911f94f901f730f4486d82dd4835d7d2772a050b 100644 (file)
--- a/ext/gd/libgd/gd.c
+++ b/ext/gd/libgd/gd.c
@@ -3873,16 +3873,15 @@ int gdImageConvolution(gdImagePtr src, float filter[3][3], float filter_div, flo
 
        /* We need the orinal image with each safe neoghb. pixel */
        srcback = gdImageCreateTrueColor (src->sx, src->sy);
+       if (srcback==NULL) {
+               return 0;
+       }
        srcback->saveAlphaFlag = 1;
        srctrans = gdImageColorAllocateAlpha(srcback, 0, 0, 0, 127);
        gdImageFill(srcback, 0, 0, srctrans);
 
        gdImageCopy(srcback, src,0,0,0,0,src->sx,src->sy);
 
-       if (srcback==NULL) {
-               return 0;
-       }
-
        f = GET_PIXEL_FUNCTION(src);
 
        for ( y=0; y<src->sy; y++) {
@@ -3939,11 +3938,10 @@ int gdImageSelectiveBlur( gdImagePtr src)
 
        /* We need the orinal image with each safe neoghb. pixel */
        srcback = gdImageCreateTrueColor (src->sx, src->sy);
-       gdImageCopy(srcback, src,0,0,0,0,src->sx,src->sy);
-
        if (srcback==NULL) {
                return 0;
        }
+       gdImageCopy(srcback, src,0,0,0,0,src->sx,src->sy);
 
        f = GET_PIXEL_FUNCTION(src);