• Gábor Szeder's avatar
    object_as_type: initialize commit-graph-related fields of 'struct commit' · 4468d443
    Gábor Szeder authored
    When the commit graph and generation numbers were introduced in
    commits 177722b3 (commit: integrate commit graph with commit
    parsing, 2018-04-10) and 83073cc9 (commit: add generation number to
    struct commit, 2018-04-25), they tried to make sure that the
    corresponding 'graph_pos' and 'generation' fields of 'struct commit'
    are initialized conservatively, as if the commit were not included in
    the commit-graph file.
    Alas, initializing those fields only in alloc_commit_node() missed the
    case when an object that happens to be a commit is first looked up via
    lookup_unknown_object(), and is then later converted to a 'struct
    commit' via the object_as_type() helper function (either calling it
    directly, or as part of a subsequent lookup_commit() call).
    Consequently, both of those fields incorrectly remain set to zero,
    which means e.g. that the commit is present in and is the first entry
    of the commit-graph file.  This will result in wrong timestamp, parent
    and root tree hashes, if such a 'struct commit' instance is later
    filled from the commit-graph.
    Extract the initialization of 'struct commit's fields from
    alloc_commit_node() into a helper function, and call it from
    object_as_type() as well, to make sure that it properly initializes
    the two commit-graph-related fields, too.  With this helper function
    it is hopefully less likely that any new fields added to 'struct
    commit' in the future would remain uninitialized.
    With this change alloc_commit_index() won't have any remaining callers
    outside of 'alloc.c', so mark it as static.
    Signed-off-by: Gábor Szeder's avatarSZEDER Gábor <szeder.dev@gmail.com>
    Signed-off-by: default avatarJunio C Hamano <gitster@pobox.com>
alloc.h 549 Bytes