If image sizes are greater than 32768, fixed point stepping will overflow an int. This CL changes t…

unit_test/unit_test.h

Index: unit_test/unit_test.h
diff --git a/unit_test/unit_test.h b/unit_test/unit_test.h
index 009ff62abf682218f4ecf7bed49e2d3d4435a87f..ae9c9c20b80bf0b92b62e1a85777e2e43d4a81ce 100644
--- a/unit_test/unit_test.h
+++ b/unit_test/unit_test.h
@@ -28,6 +28,32 @@ static __inline int Abs(int v) {
 
 #define OFFBY 0
 
+// Scaling uses 16.16 fixed point to step thru the source image, so a
+// maximum size of 32767.999 can be expressed.  32768 is valid because
+// the step is 1 beyond the image but not used.
+// Destination size is mainly constrained by valid scale step not the 
+// absolute size, so it may be possible to relax the destination size
+// constraint.
+// Source size is unconstrained for most specialized scalers.  e.g.
+// An image of 65536 scaled to half size would be valid.  The test 
+// could be relaxed for special scale factors.
+// If this test is removed, the scaling function should gracefully
+// fail with a return code.  The test could be changed to know that
+// libyuv failed in a controlled way.
+
+static const int kMaxWidth = 32768;
+static const int kMaxHeight = 32768;
+
+static inline bool SizeValid(int src_width, int src_height,
+                             int dst_width, int dst_height) {
+  if (src_width > kMaxWidth || src_height > kMaxHeight ||
+      dst_width > kMaxWidth || dst_height > kMaxHeight) {
+    printf("Warning - size too large to test.  Skipping\n");
+    return false;
+  }
+  return true;
+}
+
 #define align_buffer_page_end(var, size)                                       \
   uint8* var;                                                                  \
   uint8* var##_mem;                                                            \