0002-ubsan-error-fixes.patch revision 4d3acf4ec42bf6e838f9060103aff98fbf170794 
1diff --git a/third_party/agg23/agg_clip_liang_barsky.h b/third_party/agg23/agg_clip_liang_barsky.h
2index db6ca97..5b1261f 100644
3--- a/third_party/agg23/agg_clip_liang_barsky.h
4+++ b/third_party/agg23/agg_clip_liang_barsky.h
5@@ -20,6 +20,7 @@
6 #ifndef AGG_CLIP_LIANG_BARSKY_INCLUDED
7 #define AGG_CLIP_LIANG_BARSKY_INCLUDED
8 #include "agg_basics.h"
9+#include "third_party/base/numerics/safe_math.h"
10 namespace agg
11 {
12 template<class T>
13@@ -36,8 +37,18 @@ inline unsigned clip_liang_barsky(T x1, T y1, T x2, T y2,
14                                   T* x, T* y)
15 {
16     const FX_FLOAT nearzero = 1e-30f;
17-    FX_FLOAT deltax = (FX_FLOAT)(x2 - x1);
18-    FX_FLOAT deltay = (FX_FLOAT)(y2 - y1);
19+
20+    pdfium::base::CheckedNumeric<FX_FLOAT> width = x2;
21+    width -= x1;
22+    if (!width.IsValid())
23+        return 0;
24+    pdfium::base::CheckedNumeric<FX_FLOAT> height = y2;
25+    height -= y1;
26+    if (!height.IsValid())
27+        return 0;
28+
29+    FX_FLOAT deltax = width.ValueOrDefault(0);
30+    FX_FLOAT deltay = height.ValueOrDefault(0);
31     unsigned np = 0;
32     if(deltax == 0) {
33         deltax = (x1 > clip_box.x1) ? -nearzero : nearzero;
34