Fix infinite loop when using extents.
Clearing |buffer_| still actually makes sense because MemoryFile::Close()
is called twice: once explicitly from bspatch to check if Close()
succeeded, once from destructor to ensure that everything is closed. And
if we don't clear |buffer_|, on the second Close(), it will try to write
|buffer_| to |file_| again, and if |file_| is an ExtentsFile, it will
simply return true and set |bytes_written| to 0 on Write() because all
the extents are already written, now WriteAll() became an infinite
loop.
Although returning false if written is 0 in WriteAll() will fix this, but
I think we should not write the same buffer again in the first place.
Test: call bspatch with extents
Bug: 25773600
Change-Id: If3bddcc6e8ca6751c422c066e5b8b02f91086ed5
diff --git a/bspatch.cc b/bspatch.cc
index aae6118..550c6c7 100644
--- a/bspatch.cc
+++ b/bspatch.cc
@@ -112,7 +112,7 @@
size_t size) {
size_t offset = 0, written;
while (offset < size) {
- if (!file->Write(data + offset, size - offset, &written))
+ if (!file->Write(data + offset, size - offset, &written) || written == 0)
return false;
offset += written;
}
diff --git a/memory_file.cc b/memory_file.cc
index 996a10e..59e2c7d 100644
--- a/memory_file.cc
+++ b/memory_file.cc
@@ -35,6 +35,9 @@
bool MemoryFile::Close() {
if (!WriteAll(file_, buffer_.data(), buffer_.size()))
return false;
+ // Prevent writing |buffer_| to |file_| again if Close() is called more than
+ // once.
+ buffer_.clear();
return file_->Close();
}
