# [RFC/PATCH] merge-base: teach "git merge-base" to accept more than 2 arguments 3 messages from 2008-07-26 to 2008-07-26. Participants: Christian Couder, Johannes Schindelin, Junio C Hamano. Thread: https://gitlist.dev/t/14683 ## Christian Couder, 2008-07-26 03:59 Subject: [RFC/PATCH] merge-base: teach "git merge-base" to accept more than 2 arguments Message-ID: <20080726055920.3a2fc8e7.chriscool@tuxfamily.org> URL: https://gitlist.dev/e/20080726055920.3a2fc8e7.chriscool%40tuxfamily.org ``` Before this patch "git merge-base" accepted only 2 arguments, so only merge bases between 2 references could be computed. The purpose of this patch is to make "git merge-base" accept more than 2 arguments so that the merge bases between the first given reference and all the other references can be computed. This is easily implemented because the "get_merge_bases_many" function in "commit.c" already implements the computation. Signed-off-by: Christian Couder --- builtin-merge-base.c | 51 ++++++++++++++++++++++++++++++++++++------------- commit.h | 2 + 2 files changed, 39 insertions(+), 14 deletions(-) I suspect this patch may be usefull to simplify my "bisect: add merge bases check" series and perhaps also generally usefull. I will add documentation and perhaps tests too if people are ok with something like that. By the way perhaps such a patch has already been posted by someone else. In this case sorry for the noise and thanks for any pointer to the previous patch. diff --git a/builtin-merge-base.c b/builtin-merge-base.c index 1cb2925..9c41849 100644 --- a/builtin-merge-base.c +++ b/builtin-merge-base.c @@ -2,9 +2,14 @@ #include "cache.h" #include "commit.h" -static int show_merge_base(struct commit *rev1, struct commit *rev2, int show_all) +static struct commit *rev1, **prev2; +static size_t prev2_nr, prev2_alloc; + + +static int show_merge_base(int show_all) { - struct commit_list *result = get_merge_bases(rev1, rev2, 0); + struct commit_list *result = get_merge_bases_many(rev1, prev2_nr, + prev2, 0); if (!result) return 1; @@ -20,12 +25,24 @@ static int show_merge_base(struct commit *rev1, struct commit *rev2, int show_al } static const char merge_base_usage[] = -"git merge-base [--all]

"; +"git merge-base [--all]

..."; + +static void append_rev2(struct commit *rev) +{ + ALLOC_GROW(prev2, prev2_nr + 1, prev2_alloc); + prev2[prev2_nr++] = rev; +} + +static struct commit *get_commit_reference(const char *arg) +{ + unsigned char revkey[20]; + if (get_sha1(arg, revkey)) + die("Not a valid object name %s", arg); + return lookup_commit_reference(revkey); +} int cmd_merge_base(int argc, const char **argv, const char *prefix) { - struct commit *rev1, *rev2; - unsigned char rev1key[20], rev2key[20]; int show_all = 0; git_config(git_default_config, NULL); @@ -38,15 +55,21 @@ int cmd_merge_base(int argc, const char **argv, const char *prefix) usage(merge_base_usage); argc--; argv++; } - if (argc != 3) + if (argc < 3) usage(merge_base_usage); - if (get_sha1(argv[1], rev1key)) - die("Not a valid object name %s", argv[1]); - if (get_sha1(argv[2], rev2key)) - die("Not a valid object name %s", argv[2]); - rev1 = lookup_commit_reference(rev1key); - rev2 = lookup_commit_reference(rev2key); - if (!rev1 || !rev2) + + rev1 = get_commit_reference(argv[1]); + if (!rev1) return 1; - return show_merge_base(rev1, rev2, show_all); + argc--; argv++; + + do { + struct commit *rev2 = get_commit_reference(argv[1]); + if (!rev2) + return 1; + append_rev2(rev2); + argc--; argv++; + } while (argc > 1); + + return show_merge_base(show_all); } diff --git a/commit.h b/commit.h index 77de962..4829a5c 100644 --- a/commit.h +++ b/commit.h @@ -121,6 +121,8 @@ int read_graft_file(const char *graft_file); struct commit_graft *lookup_commit_graft(const unsigned char *sha1); extern struct commit_list *get_merge_bases(struct commit *rev1, struct commit *rev2, int cleanup); +extern struct commit_list *get_merge_bases_many(struct commit *one, + int n, struct commit **twos, int cleanup); extern struct commit_list *get_octopus_merge_bases(struct commit_list *in); extern int register_shallow(const unsigned char *sha1); -- 1.6.0.rc0.43.g62478.dirty ``` ## Johannes Schindelin, 2008-07-26 04:25 Subject: Re: [RFC/PATCH] merge-base: teach "git merge-base" to accept more than 2 arguments Message-ID: URL: https://gitlist.dev/e/alpine.DEB.1.00.0807260624210.26810%40eeepc-johanness In-Reply-To: <20080726055920.3a2fc8e7.chriscool@tuxfamily.org> ``` Hi, On Sat, 26 Jul 2008, Christian Couder wrote: > I suspect this patch may be usefull to simplify my > "bisect: add merge bases check" series and perhaps > also generally usefull. s/usefull/useful/ > diff --git a/builtin-merge-base.c b/builtin-merge-base.c > index 1cb2925..9c41849 100644 > --- a/builtin-merge-base.c > +++ b/builtin-merge-base.c > @@ -2,9 +2,14 @@ > #include "cache.h" > #include "commit.h" > > -static int show_merge_base(struct commit *rev1, struct commit *rev2, int show_all) > +static struct commit *rev1, **prev2; > +static size_t prev2_nr, prev2_alloc; > + > + > +static int show_merge_base(int show_all) > { Changing the arguments to be static variables? NACK! Ciao, Dscho ``` ## Junio C Hamano, 2008-07-26 04:37 Subject: Re: [RFC/PATCH] merge-base: teach "git merge-base" to accept more than 2 arguments Message-ID: <7vzlo5mfbf.fsf@gitster.siamese.dyndns.org> URL: https://gitlist.dev/e/7vzlo5mfbf.fsf%40gitster.siamese.dyndns.org In-Reply-To: <20080726055920.3a2fc8e7.chriscool@tuxfamily.org> ``` Christian Couder writes: > Before this patch "git merge-base" accepted only 2 arguments, so > only merge bases between 2 references could be computed. > > The purpose of this patch is to make "git merge-base" accept more > than 2 arguments so that the merge bases between the first given > reference and all the other references can be computed. I think this is a logical conclusion of merge_bases_many(). You need tests and docs, though. ```