Fix PartialCircularBuffer OOB memcpy().

chrome/common/partial_circular_buffer_unittest.cc

Index: chrome/common/partial_circular_buffer_unittest.cc
diff --git a/chrome/common/partial_circular_buffer_unittest.cc b/chrome/common/partial_circular_buffer_unittest.cc
index 85153fac8d1e21f3cf1ca041fa9ea86dc8b75a59..38a920799ade6675587e2bbf082c739ba278d98d 100644
--- a/chrome/common/partial_circular_buffer_unittest.cc
+++ b/chrome/common/partial_circular_buffer_unittest.cc
@@ -189,3 +189,24 @@ TEST_F(PartialCircularBufferTest, WrapOnceThenOverwriteWithNoWrap) {
 
   EXPECT_EQ(0u, pcb_read_->Read(output_data, sizeof(output_data)));
 }
+
+TEST_F(PartialCircularBufferTest, WrapTwiceWithSingleWrite) {
+  size_t input_size = sizeof(kInputData);

[Nico, 2015/04/07 16:42:16]

const size_t kInputSize

[gzobqq, 2015/04/08 12:59:03]

Done.

+  size_t large_size = input_size * 7;

[Nico, 2015/04/07 16:42:16]

const size_t kLargeSize

[gzobqq, 2015/04/08 12:59:03]

Done.

+  scoped_ptr<uint8[]> large_input(new uint8[large_size]);

[Nico, 2015/04/07 16:42:16]

Shouldn't this easily fit on the stack?

[gzobqq, 2015/04/08 12:59:03]

Done.

+  for (size_t offset = 0; offset < large_size; offset += input_size)
+    memcpy(large_input.get() + offset, kInputData, input_size);
+
+  InitWriteBuffer(false);
+  pcb_write_->Write(large_input.get(), large_size);
+  InitReadBuffer();
+
+  uint8 output_data[sizeof(kOutputRefDataWrap)] = {0};
+  EXPECT_EQ(sizeof(output_data),
+            pcb_read_->Read(output_data, sizeof(output_data)));
+
+  EXPECT_EQ(0, memcmp(kOutputRefDataWrap, output_data, sizeof(output_data)));
+
+  EXPECT_EQ(0u, pcb_read_->Read(output_data, sizeof(output_data)));
+}
+