tests: Add some assertions to check for zero-dimensioned images

This could happen if something in the test fails, so this allows early
diagnosis of problems. It also hints to Coverity that the loops which
follow can’t run (almost) infinitely due to the loop bounds being
inverted.

Coverity IDs: 1391987, 1399712

https://bugzilla.gnome.org/show_bug.cgi?id=778943

1 files changed, 21 insertions, 10 deletions

diff --git a/tests/pixbuf-scale-two-step.c b/tests/pixbuf-scale-two-step.c
index 8050b30c5..d3f68861a 100644
--- a/tests/pixbuf-scale-two-step.c
+++ b/tests/pixbuf-scale-two-step.c
@@ -62,26 +62,30 @@ pixdata_almost_equal (GdkPixbuf *one, GdkPixbuf *two)
   guchar *two_row;      /* Pointer to start of row of pixels in two */
   guchar *two_pixel;    /* Pointer to current pixel data in two */
   guint x, y;
+  gint width_one, height_one;
 
-  g_assert_cmpint (gdk_pixbuf_get_height (one), >=, 0);
-  g_assert_cmpint (gdk_pixbuf_get_width (one), >=, 0);
+  width_one = gdk_pixbuf_get_width (one);
+  height_one = gdk_pixbuf_get_height (one);
+
+  g_assert_cmpint (height_one, >=, 0);
+  g_assert_cmpint (width_one, >=, 0);
   g_assert_cmpint (gdk_pixbuf_get_height (two), >=, 0);
   g_assert_cmpint (gdk_pixbuf_get_width (two), >=, 0);
 
-  if (gdk_pixbuf_get_width (one) != gdk_pixbuf_get_width (two) ||
-      gdk_pixbuf_get_height (one) != gdk_pixbuf_get_height (two))
+  if (width_one != gdk_pixbuf_get_width (two) ||
+      height_one != gdk_pixbuf_get_height (two))
     {
       g_test_fail();
     }
 
   for (y = 0, one_row = gdk_pixbuf_get_pixels (one),
               two_row = gdk_pixbuf_get_pixels (two);
-       y < gdk_pixbuf_get_height (one);
+       y < height_one;
        y++, one_row += gdk_pixbuf_get_rowstride (one),
             two_row += gdk_pixbuf_get_rowstride (two))
     {
       for (x = 0, one_pixel = one_row, two_pixel = two_row;
-	   x < gdk_pixbuf_get_width(one);
+	   x < width_one;
 	   x++, one_pixel += gdk_pixbuf_get_n_channels (one),
 	        two_pixel += gdk_pixbuf_get_n_channels (two))
         {
@@ -188,21 +192,28 @@ crop_n_compare(const GdkPixbuf *source,	/* The source image */
     guchar *cropped_row;    /* Pointer to start of row of pixels in cropped */
     guchar *cropped_pixel;  /* Pointer to current pixel data in cropped */
     guint x, y;
+    gint scaled_width, scaled_height;
+
+    scaled_width = gdk_pixbuf_get_width (scaled);
+    scaled_height = gdk_pixbuf_get_height (scaled);
+
+    g_assert (scaled_width > 0);
+    g_assert (scaled_height > 0);
 
-    if (gdk_pixbuf_get_width (scaled) != gdk_pixbuf_get_width (cropped) ||
-	gdk_pixbuf_get_height (scaled) != gdk_pixbuf_get_height (cropped))
+    if (scaled_width != gdk_pixbuf_get_width (cropped) ||
+	scaled_height != gdk_pixbuf_get_height (cropped))
       {
         g_test_fail();
       }
 
     for (y = 0, scaled_row = gdk_pixbuf_get_pixels (scaled),
 	       cropped_row = gdk_pixbuf_get_pixels (cropped);
-	 y < gdk_pixbuf_get_height (scaled);
+	 y < scaled_height;
 	 y++, scaled_row += gdk_pixbuf_get_rowstride (scaled),
 	      cropped_row += gdk_pixbuf_get_rowstride (cropped))
       {
         for (x = 0, scaled_pixel = scaled_row, cropped_pixel = cropped_row;
-	    x < gdk_pixbuf_get_width(scaled);
+	    x < scaled_width;
 	    x++, scaled_pixel += gdk_pixbuf_get_n_channels (scaled),
 	         cropped_pixel += gdk_pixbuf_get_n_channels (cropped))
 	  {