dereferences and invalid file descriptor accesses flagged by
Coverity.
+ * The in-tree 'b4' cover letter template has been updated to include the
+ 'change-id' trailer, ensuring that sent tags generated by 'b4' contain
+ the required tracking information for subsequent runs.
+
Fixes since v2.55
-----------------
split commit-graph chain, causing topological levels for commits in
base layers to be recomputed during incremental writes. This has been
corrected.
+
+ * The stream-based object signature verification path has been
+ corrected to avoid double-closing the stream on read errors.
+ (merge cfd52a74a0 ps/odb-stream-double-close-fix later to maint).