From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 10 Jan 2014 18:33:32 +0000 (-0800)
Subject: Merge branch 'bm/merge-base-octopus-dedup'
X-Git-Tag: v1.9-rc0~24
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/d5d1678b9c675a97b3ec3aaf843d02b1cf536c74?ds=inline;hp=-c

Merge branch 'bm/merge-base-octopus-dedup'

"git merge-base --octopus" used to leave cleaning up suboptimal
result to the caller, but now it does the clean-up itself.

* bm/merge-base-octopus-dedup:
merge-base --octopus: reduce the result from get_octopus_merge_bases()
merge-base: separate "--independent" codepath into its own helper
---

d5d1678b9c675a97b3ec3aaf843d02b1cf536c74
diff --combined builtin/merge-base.c
index a2923235e1,87f4dbccae..0ecde8da30
--- a/builtin/merge-base.c
+++ b/builtin/merge-base.c
@@@ -1,9 -1,6 +1,9 @@@
  #include "builtin.h"
  #include "cache.h"
  #include "commit.h"
 +#include "refs.h"
 +#include "diff.h"
 +#include "revision.h"
  #include "parse-options.h"
  
  static int show_merge_base(struct commit **rev, int rev_nr, int show_all)
@@@ -30,7 -27,6 +30,7 @@@ static const char * const merge_base_us
  	N_("git merge-base [-a|--all] --octopus <commit>..."),
  	N_("git merge-base --independent <commit>..."),
  	N_("git merge-base --is-ancestor <commit> <commit>"),
 +	N_("git merge-base --fork-point <ref> [<commit>]"),
  	NULL
  };
  
@@@ -48,19 -44,36 +48,36 @@@ static struct commit *get_commit_refere
  	return r;
  }
  
- static int handle_octopus(int count, const char **args, int reduce, int show_all)
+ static int handle_independent(int count, const char **args)
  {
  	struct commit_list *revs = NULL;
  	struct commit_list *result;
  	int i;
  
- 	if (reduce)
- 		show_all = 1;
+ 	for (i = count - 1; i >= 0; i--)
+ 		commit_list_insert(get_commit_reference(args[i]), &revs);
+ 
+ 	result = reduce_heads(revs);
+ 	if (!result)
+ 		return 1;
+ 
+ 	while (result) {
+ 		printf("%s\n", sha1_to_hex(result->item->object.sha1));
+ 		result = result->next;
+ 	}
+ 	return 0;
+ }
+ 
+ static int handle_octopus(int count, const char **args, int show_all)
+ {
+ 	struct commit_list *revs = NULL;
+ 	struct commit_list *result;
+ 	int i;
  
  	for (i = count - 1; i >= 0; i--)
  		commit_list_insert(get_commit_reference(args[i]), &revs);
  
- 	result = reduce ? reduce_heads(revs) : get_octopus_merge_bases(revs);
+ 	result = reduce_heads(get_octopus_merge_bases(revs));
  
  	if (!result)
  		return 1;
@@@ -89,149 -102,40 +106,152 @@@ static int handle_is_ancestor(int argc
  		return 1;
  }
  
 +struct rev_collect {
 +	struct commit **commit;
 +	int nr;
 +	int alloc;
 +	unsigned int initial : 1;
 +};
 +
 +static void add_one_commit(unsigned char *sha1, struct rev_collect *revs)
 +{
 +	struct commit *commit;
 +
 +	if (is_null_sha1(sha1))
 +		return;
 +
 +	commit = lookup_commit(sha1);
 +	if (!commit ||
 +	    (commit->object.flags & TMP_MARK) ||
 +	    parse_commit(commit))
 +		return;
 +
 +	ALLOC_GROW(revs->commit, revs->nr + 1, revs->alloc);
 +	revs->commit[revs->nr++] = commit;
 +	commit->object.flags |= TMP_MARK;
 +}
 +
 +static int collect_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 +				  const char *ident, unsigned long timestamp,
 +				  int tz, const char *message, void *cbdata)
 +{
 +	struct rev_collect *revs = cbdata;
 +
 +	if (revs->initial) {
 +		revs->initial = 0;
 +		add_one_commit(osha1, revs);
 +	}
 +	add_one_commit(nsha1, revs);
 +	return 0;
 +}
 +
 +static int handle_fork_point(int argc, const char **argv)
 +{
 +	unsigned char sha1[20];
 +	char *refname;
 +	const char *commitname;
 +	struct rev_collect revs;
 +	struct commit *derived;
 +	struct commit_list *bases;
 +	int i, ret = 0;
 +
 +	switch (dwim_ref(argv[0], strlen(argv[0]), sha1, &refname)) {
 +	case 0:
 +		die("No such ref: '%s'", argv[0]);
 +	case 1:
 +		break; /* good */
 +	default:
 +		die("Ambiguous refname: '%s'", argv[0]);
 +	}
 +
 +	commitname = (argc == 2) ? argv[1] : "HEAD";
 +	if (get_sha1(commitname, sha1))
 +		die("Not a valid object name: '%s'", commitname);
 +
 +	derived = lookup_commit_reference(sha1);
 +	memset(&revs, 0, sizeof(revs));
 +	revs.initial = 1;
 +	for_each_reflog_ent(refname, collect_one_reflog_ent, &revs);
 +
 +	for (i = 0; i < revs.nr; i++)
 +		revs.commit[i]->object.flags &= ~TMP_MARK;
 +
 +	bases = get_merge_bases_many(derived, revs.nr, revs.commit, 0);
 +
 +	/*
 +	 * There should be one and only one merge base, when we found
 +	 * a common ancestor among reflog entries.
 +	 */
 +	if (!bases || bases->next) {
 +		ret = 1;
 +		goto cleanup_return;
 +	}
 +
 +	/* And the found one must be one of the reflog entries */
 +	for (i = 0; i < revs.nr; i++)
 +		if (&bases->item->object == &revs.commit[i]->object)
 +			break; /* found */
 +	if (revs.nr <= i) {
 +		ret = 1; /* not found */
 +		goto cleanup_return;
 +	}
 +
 +	printf("%s\n", sha1_to_hex(bases->item->object.sha1));
 +
 +cleanup_return:
 +	free_commit_list(bases);
 +	return ret;
 +}
 +
  int cmd_merge_base(int argc, const char **argv, const char *prefix)
  {
  	struct commit **rev;
  	int rev_nr = 0;
  	int show_all = 0;
 -	int octopus = 0;
 -	int reduce = 0;
 -	int is_ancestor = 0;
 +	int cmdmode = 0;
  
  	struct option options[] = {
 -		OPT_BOOLEAN('a', "all", &show_all, N_("output all common ancestors")),
 -		OPT_BOOLEAN(0, "octopus", &octopus, N_("find ancestors for a single n-way merge")),
 -		OPT_BOOLEAN(0, "independent", &reduce, N_("list revs not reachable from others")),
 -		OPT_BOOLEAN(0, "is-ancestor", &is_ancestor,
 -			    N_("is the first one ancestor of the other?")),
 +		OPT_BOOL('a', "all", &show_all, N_("output all common ancestors")),
 +		OPT_CMDMODE(0, "octopus", &cmdmode,
 +			    N_("find ancestors for a single n-way merge"), 'o'),
 +		OPT_CMDMODE(0, "independent", &cmdmode,
 +			    N_("list revs not reachable from others"), 'r'),
 +		OPT_CMDMODE(0, "is-ancestor", &cmdmode,
 +			    N_("is the first one ancestor of the other?"), 'a'),
 +		OPT_CMDMODE(0, "fork-point", &cmdmode,
 +			    N_("find where <commit> forked from reflog of <ref>"), 'f'),
  		OPT_END()
  	};
  
  	git_config(git_default_config, NULL);
  	argc = parse_options(argc, argv, prefix, options, merge_base_usage, 0);
 -	if (!octopus && !reduce && argc < 2)
 -		usage_with_options(merge_base_usage, options);
 -	if (is_ancestor && (show_all || octopus || reduce))
 -		die("--is-ancestor cannot be used with other options");
 -	if (is_ancestor)
 +
 +	if (cmdmode == 'a') {
 +		if (argc < 2)
 +			usage_with_options(merge_base_usage, options);
 +		if (show_all)
 +			die("--is-ancestor cannot be used with --all");
  		return handle_is_ancestor(argc, argv);
 -	if (reduce && (show_all || octopus))
 -		die("--independent cannot be used with other options");
 +	}
  
 -	if (octopus)
 +	if (cmdmode == 'r' && show_all)
 +		die("--independent cannot be used with --all");
 +
- 	if (cmdmode == 'r' || cmdmode == 'o')
- 		return handle_octopus(argc, argv, cmdmode == 'r', show_all);
++	if (cmdmode == 'o')
+ 		return handle_octopus(argc, argv, show_all);
 -	else if (reduce)
++
++	if (cmdmode == 'r')
+ 		return handle_independent(argc, argv);
  
 +	if (cmdmode == 'f') {
 +		if (argc < 1 || 2 < argc)
 +			usage_with_options(merge_base_usage, options);
 +		return handle_fork_point(argc, argv);
 +	}
 +
 +	if (argc < 2)
 +		usage_with_options(merge_base_usage, options);
 +
  	rev = xmalloc(argc * sizeof(*rev));
  	while (argc-- > 0)
  		rev[rev_nr++] = get_commit_reference(*argv++);
diff --combined t/t6010-merge-base.sh
index 30a68335b3,abb5728b34..39b3238da2
--- a/t/t6010-merge-base.sh
+++ b/t/t6010-merge-base.sh
@@@ -230,32 -230,43 +230,71 @@@ test_expect_success 'criss-cross merge-
  	test_cmp expected.sorted actual.sorted
  '
  
 +test_expect_success 'using reflog to find the fork point' '
 +	git reset --hard &&
 +	git checkout -b base $E &&
 +
 +	(
 +		for count in 1 2 3
 +		do
 +			git commit --allow-empty -m "Base commit #$count" &&
 +			git rev-parse HEAD >expect$count &&
 +			git checkout -B derived &&
 +			git commit --allow-empty -m "Derived #$count" &&
 +			git rev-parse HEAD >derived$count &&
 +			git checkout -B base $E || exit 1
 +		done
 +
 +		for count in 1 2 3
 +		do
 +			git merge-base --fork-point base $(cat derived$count) >actual &&
 +			test_cmp expect$count actual || exit 1
 +		done
 +
 +	) &&
 +	# check that we correctly default to HEAD
 +	git checkout derived &&
 +	git merge-base --fork-point base >actual &&
 +	test_cmp expect3 actual
 +'
 +
+ test_expect_success 'merge-base --octopus --all for complex tree' '
+ 	# Best common ancestor for JE, JAA and JDD is JC
+ 	#             JE
+ 	#            / |
+ 	#           /  |
+ 	#          /   |
+ 	#  JAA    /    |
+ 	#   |\   /     |
+ 	#   | \  | JDD |
+ 	#   |  \ |/ |  |
+ 	#   |   JC JD  |
+ 	#   |    | /|  |
+ 	#   |    |/ |  |
+ 	#  JA    |  |  |
+ 	#   |\  /|  |  |
+ 	#   X JB |  X  X
+ 	#   \  \ | /   /
+ 	#    \__\|/___/
+ 	#        J
+ 	test_commit J &&
+ 	test_commit JB &&
+ 	git reset --hard J &&
+ 	test_commit JC &&
+ 	git reset --hard J &&
+ 	test_commit JTEMP1 &&
+ 	test_merge JA JB &&
+ 	test_merge JAA JC &&
+ 	git reset --hard J &&
+ 	test_commit JTEMP2 &&
+ 	test_merge JD JB &&
+ 	test_merge JDD JC &&
+ 	git reset --hard J &&
+ 	test_commit JTEMP3 &&
+ 	test_merge JE JC &&
+ 	git rev-parse JC >expected &&
+ 	git merge-base --all --octopus JAA JDD JE >actual &&
+ 	test_cmp expected actual
+ '
+ 
  test_done