git log: add '--merges' flag to match '--no-merges'

I do various statistics on git, and one of the things I look at is merges,
because they are often interesting events to count ("how many merges vs
how much 'real development'" kind of statistics). And you can do it with
some fairly straightforward scripting, ie

	git rev-list --parents HEAD |
		grep ' .* ' |
		git diff-tree --always -s --pretty=oneline --stdin |
		less -S

will do it.

But I finally got irritated with the fact that we can skip merges with
'--no-merges', but we can't do the trivial reverse operation.

So this just adds a '--merges' flag that _only_ shows merges. Now you can
do the above with just a

	git log --merges --pretty=oneline

which is a lot simpler. It also means that we automatically get a lot of
statistics for free, eg

	git shortlog -ns --merges

does exactly what you'd want it to do.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/revision.c b/revision.c
index bf584483675ef55b2ed9b8d8586b92d5432759a5..a31434bdc8ed19674d3c4863e009af0c40d75e73 100644 (file)
--- a/revision.c
+++ b/revision.c
@@ -1077,6 +1077,8 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
                revs->show_all = 1;
        } else if (!strcmp(arg, "--remove-empty")) {
                revs->remove_empty_trees = 1;
+       } else if (!strcmp(arg, "--merges")) {
+               revs->merges_only = 1;
        } else if (!strcmp(arg, "--no-merges")) {
                revs->no_merges = 1;
        } else if (!strcmp(arg, "--boundary")) {
@@ -1676,6 +1678,8 @@ enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
                return commit_ignore;
        if (revs->no_merges && commit->parents && commit->parents->next)
                return commit_ignore;
+       if (revs->merges_only && !(commit->parents && commit->parents->next))
+               return commit_ignore;
        if (!commit_match(commit, revs))
                return commit_ignore;
        if (revs->prune && revs->dense) {

diff --git a/revision.h b/revision.h
index 227164cf7096d3b0642714b18ee345738684da79..fb74492714b9276d02992dbe1101efff2cbdb5e6 100644 (file)
--- a/revision.h
+++ b/revision.h
@@ -36,6 +36,7 @@ struct rev_info {
        unsigned int    dense:1,
                        prune:1,
                        no_merges:1,
+                       merges_only:1,
                        no_walk:1,
                        show_all:1,
                        remove_empty_trees:1,