Make SkROBuffer::Iter::size() work when exhausted
According to the documentation, this method will return 0 when the Iter
is exhausted. Prior to this CL, it crashes instead.
Prevent a crash with a null fHead, and add a test to verify the
behavior.
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1574603002
Review URL: https://codereview.chromium.org/1574603002
diff --git a/tests/DataRefTest.cpp b/tests/DataRefTest.cpp
index 0c7d5f4..f1e645e 100644
--- a/tests/DataRefTest.cpp
+++ b/tests/DataRefTest.cpp
@@ -313,3 +313,18 @@
delete streams[i];
}
}
+
+// Tests that it is safe to call SkROBuffer::Iter::size() when exhausted.
+DEF_TEST(RWBuffer_size, r) {
+ SkRWBuffer buffer;
+ buffer.append(gABC, 26);
+
+ SkAutoTUnref<SkROBuffer> roBuffer(buffer.newRBufferSnapshot());
+ SkROBuffer::Iter iter(roBuffer);
+ REPORTER_ASSERT(r, iter.data());
+ REPORTER_ASSERT(r, iter.size() == 26);
+
+ // There is only one block in this buffer.
+ REPORTER_ASSERT(r, !iter.next());
+ REPORTER_ASSERT(r, 0 == iter.size());
+}