drm_hwcomposer: filter out empty or invalid rects.
We can safely ignore zero-area rects because they do not affect the outcome
of the separate_rects() function. Furthermore the line sweep algorithm would
break when two identical START or END events are added to the same set.
Additionally any rect with |left| greater than |right| or |top| greater than
|bottom| is invalid and shall be ignored.
Added test cases with empty and invalid rects. This case would have crashed (or
failed the assert in a debug build) without this fix.
BUG=chrome-os-partner:47103
TEST=verify no crash with Photos app
Change-Id: I80950ef376390a14a892c58b563eb3c0f79db71c
diff --git a/seperate_rects.cpp b/seperate_rects.cpp
index 06fbe39..9344873 100644
--- a/seperate_rects.cpp
+++ b/seperate_rects.cpp
@@ -108,6 +108,11 @@
// algorithm sweeps from left to right.
for (TId i = 0; i < in.size(); i++) {
const Rect<TNum> &rect = in[i];
+
+ // Filter out empty or invalid rects.
+ if (rect.left >= rect.right || rect.top >= rect.bottom)
+ continue;
+
SweepEvent<TId, TNum> evt;
evt.rect_id = i;
@@ -346,6 +351,11 @@
in.push_back({50, 51, 52, 53});
in.push_back({50, 51, 52, 53});
+ in.push_back({0, 0, 0, 10});
+ in.push_back({0, 0, 10, 0});
+ in.push_back({10, 0, 0, 10});
+ in.push_back({0, 10, 10, 0});
+
for (int i = 0; i < 100000; i++) {
out.clear();
seperate_rects(in, &out);
