Snap for 6877993 from 669090928a6a6e87f36d07d63c14ea1b97f38d37 to rvc-qpr1-release

Change-Id: Ib970f7c29150ecf2b5c2cb0fb878be05a921efd0

services/surfaceflinger/Layer.cpp

diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 3b9c7b7..e9965d4 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -2410,7 +2410,15 @@
     xSurfaceInset = (xSurfaceInset >= 0) ? std::min(xSurfaceInset, layerBounds.getWidth() / 2) : 0;
     ySurfaceInset = (ySurfaceInset >= 0) ? std::min(ySurfaceInset, layerBounds.getHeight() / 2) : 0;
 
-    layerBounds.inset(xSurfaceInset, ySurfaceInset, xSurfaceInset, ySurfaceInset);
+    // inset while protecting from overflow TODO(b/161235021): What is going wrong
+    // in the overflow scenario?
+    {
+    int32_t tmp;
+    if (!__builtin_add_overflow(layerBounds.left, xSurfaceInset, &tmp)) layerBounds.left = tmp;
+    if (!__builtin_sub_overflow(layerBounds.right, xSurfaceInset, &tmp)) layerBounds.right = tmp;
+    if (!__builtin_add_overflow(layerBounds.top, ySurfaceInset, &tmp)) layerBounds.top = tmp;
+    if (!__builtin_sub_overflow(layerBounds.bottom, ySurfaceInset, &tmp)) layerBounds.bottom = tmp;
+    }
 
     // Input coordinate should match the layer bounds.
     info.frameLeft = layerBounds.left;