Merge branch 'jk/commit-buffer-length'

Move "commit->buffer" out of the in-core commit object and keep track of their lengths. Use this to optimize the code paths to validate GPG signatures in commit objects. * jk/commit-buffer-length: reuse cached commit buffer when parsing signatures commit: record buffer length in cache commit: convert commit->buffer to a slab commit-slab: provide a static initializer use get_commit_buffer everywhere convert logmsg_reencode to get_commit_buffer use get_commit_buffer to avoid duplicate code use get_cached_commit_buffer where appropriate provide helpers to access the commit buffer provide a helper to set the commit buffer provide a helper to free commit buffer sequencer: use logmsg_reencode in get_message logmsg_reencode: return const buffer do not create "struct commit" with xcalloc commit: push commit_index update into alloc_commit_node alloc: include any-object allocations in alloc_report replace dangerous uses of strbuf_attach commit_tree: take a pointer/len pair rather than a const strbuf