From d42c9ffa0fa169ea51c971d1143b3f20d5a32d83 Mon Sep 17 00:00:00 2001 From: Phillip Wood Date: Mon, 17 Oct 2022 13:17:43 +0000 Subject: [PATCH] rebase: factor out branch_base calculation Separate out calculating the merge base between 'onto' and 'HEAD' from the check for whether we can fast-forward or not. This means we can skip the fast-forward checks when the rebase is forced and avoid calculating the merge-base between 'HEAD' and 'onto' when --keep-base is given. Signed-off-by: Phillip Wood Signed-off-by: Junio C Hamano --- builtin/rebase.c | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-) diff --git a/builtin/rebase.c b/builtin/rebase.c index 74024f49df..9ee3ab6240 100644 --- a/builtin/rebase.c +++ b/builtin/rebase.c @@ -865,13 +865,9 @@ static int can_fast_forward(struct commit *onto, struct commit *upstream, struct commit_list *merge_bases = NULL; int res = 0; - merge_bases = get_merge_bases(onto, head); - if (!merge_bases || merge_bases->next) { - oidcpy(branch_base, null_oid()); - goto done; - } + if (is_null_oid(branch_base)) + goto done; /* fill_branch_base() found multiple merge bases */ - oidcpy(branch_base, &merge_bases->item->object.oid); if (!oideq(branch_base, &onto->object.oid)) goto done; @@ -881,7 +877,6 @@ static int can_fast_forward(struct commit *onto, struct commit *upstream, if (!upstream) goto done; - free_commit_list(merge_bases); merge_bases = get_merge_bases(upstream, head); if (!merge_bases || merge_bases->next) goto done; @@ -896,6 +891,20 @@ static int can_fast_forward(struct commit *onto, struct commit *upstream, return res && is_linear_history(onto, head); } +static void fill_branch_base(struct rebase_options *options, + struct object_id *branch_base) +{ + struct commit_list *merge_bases = NULL; + + merge_bases = get_merge_bases(options->onto, options->orig_head); + if (!merge_bases || merge_bases->next) + oidcpy(branch_base, null_oid()); + else + oidcpy(branch_base, &merge_bases->item->object.oid); + + free_commit_list(merge_bases); +} + static int parse_opt_am(const struct option *opt, const char *arg, int unset) { struct rebase_options *opts = opt->value; @@ -1660,6 +1669,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix) if (!options.onto) die(_("Does not point to a valid commit '%s'"), options.onto_name); + fill_branch_base(&options, &branch_base); } if (options.fork_point > 0) @@ -1689,13 +1699,10 @@ int cmd_rebase(int argc, const char **argv, const char *prefix) * Check if we are already based on onto with linear history, * in which case we could fast-forward without replacing the commits * with new commits recreated by replaying their changes. - * - * Note that can_fast_forward() initializes branch_base, so we have to - * call it before checking allow_preemptive_ff. */ - if (can_fast_forward(options.onto, options.upstream, options.restrict_revision, - options.orig_head, &branch_base) && - allow_preemptive_ff) { + if (allow_preemptive_ff && + can_fast_forward(options.onto, options.upstream, options.restrict_revision, + options.orig_head, &branch_base)) { int flag; if (!(options.flags & REBASE_FORCE)) {