On Tue, 3 Apr 2018 12:51:38 -0400 Derrick Stolee <dstolee@xxxxxxxxxxxxx> wrote: > Most code paths load commits using lookup_commit() and then > parse_commit(). In some cases, including some branch lookups, the commit > is parsed using parse_object_buffer() which side-steps parse_commit() in > favor of parse_commit_buffer(). > > Before adding generation numbers to the commit-graph, we need to ensure > that any commit that exists in the graph is loaded from the graph, so > check parse_commit_in_graph() before calling parse_commit_buffer(). > > Signed-off-by: Derrick Stolee <dstolee@xxxxxxxxxxxxx> Modifying parse_object_buffer() is the most pragmatic way to accomplish this, but this also means that parse_object_buffer() now potentially reads from the local object store (instead of only relying on what's in memory and what's in the provided buffer). parse_object_buffer() is called by several callers including in builtin/fsck.c. I would feel more comfortable if the relevant [1] caller to parse_object_buffer() was modified instead of parse_object_buffer(), but I'll let others give their opinions too. [1] The caller which, if modified, will result in the speedup to the merge-base calculations in the Windows repository you describe in your cover letter.