Fix use-after-free in unittest setup code.
When setting the root prefix in a unittest, we need to reset it after
so it isn't accidentally used by other tests.
Bug: chromium:547127
Test: USE="clang asan" FEATURES=test emerge-link update_engine
Change-Id: Ib84bbf265a380976407100a4fba4d2600d62dde6
diff --git a/image_properties.h b/image_properties.h
index 8f8c0f6..6026c2e 100644
--- a/image_properties.h
+++ b/image_properties.h
@@ -74,7 +74,7 @@
const MutableImageProperties& properties);
// Sets the root_prefix used to load files from during unittests to
-// |test_root_prefix|.
+// |test_root_prefix|. Passing a nullptr value resets it to the default.
namespace test {
void SetImagePropertiesRootPrefix(const char* test_root_prefix);
} // namespace test