1 files changed, 12 insertions, 0 deletions
diff --git a/third_party/rust/mp4parse/src/macros.rs b/third_party/rust/mp4parse/src/macros.rs
new file mode 100644
index 0000000000..a893f7e1ac
--- /dev/null
+++ b/third_party/rust/mp4parse/src/macros.rs
@@ -0,0 +1,12 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+macro_rules! check_parser_state {
+    ( $src:expr ) => {
+        if $src.limit() > 0 {
+            debug!("bad parser state: {} content bytes left", $src.limit());
+            return Err(Error::InvalidData("unread box content or bad parser sync"));
+        }
+    };
+}