1 files changed, 282 insertions, 35 deletions

diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index f8023bae1e..e782518164 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -1,13 +1,21 @@
+#define USE_THE_INDEX_VARIABLE
 #include "builtin.h"
 #include "tree-walk.h"
 #include "xdiff-interface.h"
+#include "help.h"
+#include "hex.h"
+#include "commit.h"
+#include "commit-reach.h"
+#include "merge-ort.h"
 #include "object-store.h"
+#include "parse-options.h"
 #include "repository.h"
 #include "blob.h"
 #include "exec-cmd.h"
 #include "merge-blobs.h"
+#include "quote.h"
 
-static const char merge_tree_usage[] = "git merge-tree <base-tree> <branch1> <branch2>";
+static int line_termination = '\n';
 
 struct merge_list {
 	struct merge_list *next;
@@ -27,7 +35,7 @@ static void add_merge_entry(struct merge_list *entry)
 	merge_result_end = &entry->next;
 }
 
-static void merge_trees(struct tree_desc t[3], const char *base);
+static void trivial_merge_trees(struct tree_desc t[3], const char *base);
 
 static const char *explanation(struct merge_list *entry)
 {
@@ -76,7 +84,8 @@ static void *result(struct merge_list *entry, unsigned long *size)
 	their = NULL;
 	if (entry)
 		their = entry->blob;
-	return merge_blobs(path, base, our, their, size);
+	return merge_blobs(the_repository->index, path,
+			   base, our, their, size);
 }
 
 static void *origin(struct merge_list *entry, unsigned long *size)
@@ -91,7 +100,7 @@ static void *origin(struct merge_list *entry, unsigned long *size)
 	return NULL;
 }
 
-static int show_outf(void *priv_, mmbuffer_t *mb, int nbuf)
+static int show_outf(void *priv UNUSED, mmbuffer_t *mb, int nbuf)
 {
 	int i;
 	for (i = 0; i < nbuf; i++)
@@ -105,13 +114,12 @@ static void show_diff(struct merge_list *entry)
 	mmfile_t src, dst;
 	xpparam_t xpp;
 	xdemitconf_t xecfg;
-	xdemitcb_t ecb;
+	xdemitcb_t ecb = { .out_line = show_outf };
 
+	memset(&xpp, 0, sizeof(xpp));
 	xpp.flags = 0;
 	memset(&xecfg, 0, sizeof(xecfg));
 	xecfg.ctxlen = 3;
-	ecb.outf = show_outf;
-	ecb.priv = NULL;
 
 	src.ptr = origin(entry, &size);
 	if (!src.ptr)
@@ -153,15 +161,15 @@ static void show_result(void)
 /* An empty entry never compares same, not even to another empty entry */
 static int same_entry(struct name_entry *a, struct name_entry *b)
 {
-	return	a->oid &&
-		b->oid &&
-		!oidcmp(a->oid, b->oid) &&
+	return	!is_null_oid(&a->oid) &&
+		!is_null_oid(&b->oid) &&
+		oideq(&a->oid, &b->oid) &&
 		a->mode == b->mode;
 }
 
 static int both_empty(struct name_entry *a, struct name_entry *b)
 {
-	return !(a->oid || b->oid);
+	return is_null_oid(&a->oid) && is_null_oid(&b->oid);
 }
 
 static struct merge_list *create_entry(unsigned stage, unsigned mode, const struct object_id *oid, const char *path)
@@ -177,8 +185,9 @@ static struct merge_list *create_entry(unsigned stage, unsigned mode, const stru
 
 static char *traverse_path(const struct traverse_info *info, const struct name_entry *n)
 {
-	char *path = xmallocz(traverse_path_len(info, n));
-	return make_traverse_path(path, info, n);
+	struct strbuf buf = STRBUF_INIT;
+	strbuf_make_traverse_path(&buf, info, n->path, n->pathlen);
+	return strbuf_detach(&buf, NULL);
 }
 
 static void resolve(const struct traverse_info *info, struct name_entry *ours, struct name_entry *result)
@@ -191,8 +200,8 @@ static void resolve(const struct traverse_info *info, struct name_entry *ours, s
 		return;
 
 	path = traverse_path(info, result);
-	orig = create_entry(2, ours->mode, ours->oid, path);
-	final = create_entry(0, result->mode, result->oid, path);
+	orig = create_entry(2, ours->mode, &ours->oid, path);
+	final = create_entry(0, result->mode, &result->oid, path);
 
 	final->link = orig;
 
@@ -202,6 +211,7 @@ static void resolve(const struct traverse_info *info, struct name_entry *ours, s
 static void unresolved_directory(const struct traverse_info *info,
 				 struct name_entry n[3])
 {
+	struct repository *r = the_repository;
 	char *newbase;
 	struct name_entry *p;
 	struct tree_desc t[3];
@@ -216,13 +226,13 @@ static void unresolved_directory(const struct traverse_info *info,
 
 	newbase = traverse_path(info, p);
 
-#define ENTRY_OID(e) (((e)->mode && S_ISDIR((e)->mode)) ? (e)->oid : NULL)
-	buf0 = fill_tree_descriptor(t + 0, ENTRY_OID(n + 0));
-	buf1 = fill_tree_descriptor(t + 1, ENTRY_OID(n + 1));
-	buf2 = fill_tree_descriptor(t + 2, ENTRY_OID(n + 2));
+#define ENTRY_OID(e) (((e)->mode && S_ISDIR((e)->mode)) ? &(e)->oid : NULL)
+	buf0 = fill_tree_descriptor(r, t + 0, ENTRY_OID(n + 0));
+	buf1 = fill_tree_descriptor(r, t + 1, ENTRY_OID(n + 1));
+	buf2 = fill_tree_descriptor(r, t + 2, ENTRY_OID(n + 2));
 #undef ENTRY_OID
 
-	merge_trees(t, newbase);
+	trivial_merge_trees(t, newbase);
 
 	free(buf0);
 	free(buf1);
@@ -242,7 +252,7 @@ static struct merge_list *link_entry(unsigned stage, const struct traverse_info
 		path = entry->path;
 	else
 		path = traverse_path(info, n);
-	link = create_entry(stage, n->mode, n->oid, path);
+	link = create_entry(stage, n->mode, &n->oid, path);
 	link->link = entry;
 	return link;
 }
@@ -317,7 +327,7 @@ static int threeway_callback(int n, unsigned long mask, unsigned long dirmask, s
 	}
 
 	if (same_entry(entry+0, entry+1)) {
-		if (entry[2].oid && !S_ISDIR(entry[2].mode)) {
+		if (!is_null_oid(&entry[2].oid) && !S_ISDIR(entry[2].mode)) {
 			/* We did not touch, they modified -- take theirs */
 			resolve(info, entry+1, entry+2);
 			return mask;
@@ -339,40 +349,42 @@ static int threeway_callback(int n, unsigned long mask, unsigned long dirmask, s
 	return mask;
 }
 
-static void merge_trees(struct tree_desc t[3], const char *base)
+static void trivial_merge_trees(struct tree_desc t[3], const char *base)
 {
 	struct traverse_info info;
 
 	setup_traverse_info(&info, base);
 	info.fn = threeway_callback;
-	traverse_trees(3, t, &info);
+	traverse_trees(&the_index, 3, t, &info);
 }
 
-static void *get_tree_descriptor(struct tree_desc *desc, const char *rev)
+static void *get_tree_descriptor(struct repository *r,
+				 struct tree_desc *desc,
+				 const char *rev)
 {
 	struct object_id oid;
 	void *buf;
 
-	if (get_oid(rev, &oid))
+	if (repo_get_oid(r, rev, &oid))
 		die("unknown rev %s", rev);
-	buf = fill_tree_descriptor(desc, &oid);
+	buf = fill_tree_descriptor(r, desc, &oid);
 	if (!buf)
 		die("%s is not a tree", rev);
 	return buf;
 }
 
-int cmd_merge_tree(int argc, const char **argv, const char *prefix)
+static int trivial_merge(const char *base,
+			 const char *branch1,
+			 const char *branch2)
 {
+	struct repository *r = the_repository;
 	struct tree_desc t[3];
 	void *buf1, *buf2, *buf3;
 
-	if (argc != 4)
-		usage(merge_tree_usage);
-
-	buf1 = get_tree_descriptor(t+0, argv[1]);
-	buf2 = get_tree_descriptor(t+1, argv[2]);
-	buf3 = get_tree_descriptor(t+2, argv[3]);
-	merge_trees(t, "");
+	buf1 = get_tree_descriptor(r, t+0, base);
+	buf2 = get_tree_descriptor(r, t+1, branch1);
+	buf3 = get_tree_descriptor(r, t+2, branch2);
+	trivial_merge_trees(t, "");
 	free(buf1);
 	free(buf2);
 	free(buf3);
@@ -380,3 +392,238 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 	show_result();
 	return 0;
 }
+
+enum mode {
+	MODE_UNKNOWN,
+	MODE_TRIVIAL,
+	MODE_REAL,
+};
+
+struct merge_tree_options {
+	int mode;
+	int allow_unrelated_histories;
+	int show_messages;
+	int name_only;
+	int use_stdin;
+};
+
+static int real_merge(struct merge_tree_options *o,
+		      const char *merge_base,
+		      const char *branch1, const char *branch2,
+		      const char *prefix)
+{
+	struct commit *parent1, *parent2;
+	struct commit_list *merge_bases = NULL;
+	struct merge_options opt;
+	struct merge_result result = { 0 };
+	int show_messages = o->show_messages;
+
+	parent1 = get_merge_parent(branch1);
+	if (!parent1)
+		help_unknown_ref(branch1, "merge-tree",
+				 _("not something we can merge"));
+
+	parent2 = get_merge_parent(branch2);
+	if (!parent2)
+		help_unknown_ref(branch2, "merge-tree",
+				 _("not something we can merge"));
+
+	init_merge_options(&opt, the_repository);
+
+	opt.show_rename_progress = 0;
+
+	opt.branch1 = branch1;
+	opt.branch2 = branch2;
+
+	if (merge_base) {
+		struct commit *base_commit;
+		struct tree *base_tree, *parent1_tree, *parent2_tree;
+
+		base_commit = lookup_commit_reference_by_name(merge_base);
+		if (!base_commit)
+			die(_("could not lookup commit %s"), merge_base);
+
+		opt.ancestor = merge_base;
+		base_tree = get_commit_tree(base_commit);
+		parent1_tree = get_commit_tree(parent1);
+		parent2_tree = get_commit_tree(parent2);
+		merge_incore_nonrecursive(&opt, base_tree, parent1_tree, parent2_tree, &result);
+	} else {
+		/*
+		 * Get the merge bases, in reverse order; see comment above
+		 * merge_incore_recursive in merge-ort.h
+		 */
+		merge_bases = get_merge_bases(parent1, parent2);
+		if (!merge_bases && !o->allow_unrelated_histories)
+			die(_("refusing to merge unrelated histories"));
+		merge_bases = reverse_commit_list(merge_bases);
+		merge_incore_recursive(&opt, merge_bases, parent1, parent2, &result);
+	}
+
+	if (result.clean < 0)
+		die(_("failure to merge"));
+
+	if (show_messages == -1)
+		show_messages = !result.clean;
+
+	if (o->use_stdin)
+		printf("%d%c", result.clean, line_termination);
+	printf("%s%c", oid_to_hex(&result.tree->object.oid), line_termination);
+	if (!result.clean) {
+		struct string_list conflicted_files = STRING_LIST_INIT_NODUP;
+		const char *last = NULL;
+		int i;
+
+		merge_get_conflicted_files(&result, &conflicted_files);
+		for (i = 0; i < conflicted_files.nr; i++) {
+			const char *name = conflicted_files.items[i].string;
+			struct stage_info *c = conflicted_files.items[i].util;
+			if (!o->name_only)
+				printf("%06o %s %d\t",
+				       c->mode, oid_to_hex(&c->oid), c->stage);
+			else if (last && !strcmp(last, name))
+				continue;
+			write_name_quoted_relative(
+				name, prefix, stdout, line_termination);
+			last = name;
+		}
+		string_list_clear(&conflicted_files, 1);
+	}
+	if (show_messages) {
+		putchar(line_termination);
+		merge_display_update_messages(&opt, line_termination == '\0',
+					      &result);
+	}
+	if (o->use_stdin)
+		putchar(line_termination);
+	merge_finalize(&opt, &result);
+	return !result.clean; /* result.clean < 0 handled above */
+}
+
+int cmd_merge_tree(int argc, const char **argv, const char *prefix)
+{
+	struct merge_tree_options o = { .show_messages = -1 };
+	int expected_remaining_argc;
+	int original_argc;
+	const char *merge_base = NULL;
+
+	const char * const merge_tree_usage[] = {
+		N_("git merge-tree [--write-tree] [<options>] <branch1> <branch2>"),
+		N_("git merge-tree [--trivial-merge] <base-tree> <branch1> <branch2>"),
+		NULL
+	};
+	struct option mt_options[] = {
+		OPT_CMDMODE(0, "write-tree", &o.mode,
+			    N_("do a real merge instead of a trivial merge"),
+			    MODE_REAL),
+		OPT_CMDMODE(0, "trivial-merge", &o.mode,
+			    N_("do a trivial merge only"), MODE_TRIVIAL),
+		OPT_BOOL(0, "messages", &o.show_messages,
+			 N_("also show informational/conflict messages")),
+		OPT_SET_INT('z', NULL, &line_termination,
+			    N_("separate paths with the NUL character"), '\0'),
+		OPT_BOOL_F(0, "name-only",
+			   &o.name_only,
+			   N_("list filenames without modes/oids/stages"),
+			   PARSE_OPT_NONEG),
+		OPT_BOOL_F(0, "allow-unrelated-histories",
+			   &o.allow_unrelated_histories,
+			   N_("allow merging unrelated histories"),
+			   PARSE_OPT_NONEG),
+		OPT_BOOL_F(0, "stdin",
+			   &o.use_stdin,
+			   N_("perform multiple merges, one per line of input"),
+			   PARSE_OPT_NONEG),
+		OPT_STRING(0, "merge-base",
+			   &merge_base,
+			   N_("commit"),
+			   N_("specify a merge-base for the merge")),
+		OPT_END()
+	};
+
+	/* Parse arguments */
+	original_argc = argc - 1; /* ignoring argv[0] */
+	argc = parse_options(argc, argv, prefix, mt_options,
+			     merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
+
+	/* Handle --stdin */
+	if (o.use_stdin) {
+		struct strbuf buf = STRBUF_INIT;
+
+		if (o.mode == MODE_TRIVIAL)
+			die(_("--trivial-merge is incompatible with all other options"));
+		if (merge_base)
+			die(_("--merge-base is incompatible with --stdin"));
+		line_termination = '\0';
+		while (strbuf_getline_lf(&buf, stdin) != EOF) {
+			struct strbuf **split;
+			int result;
+			const char *input_merge_base = NULL;
+
+			split = strbuf_split(&buf, ' ');
+			if (!split[0] || !split[1])
+				die(_("malformed input line: '%s'."), buf.buf);
+			strbuf_rtrim(split[0]);
+			strbuf_rtrim(split[1]);
+
+			/* parse the merge-base */
+			if (!strcmp(split[1]->buf, "--")) {
+				input_merge_base = split[0]->buf;
+			}
+
+			if (input_merge_base && split[2] && split[3] && !split[4]) {
+				strbuf_rtrim(split[2]);
+				strbuf_rtrim(split[3]);
+				result = real_merge(&o, input_merge_base, split[2]->buf, split[3]->buf, prefix);
+			} else if (!input_merge_base && !split[2]) {
+				result = real_merge(&o, NULL, split[0]->buf, split[1]->buf, prefix);
+			} else {
+				die(_("malformed input line: '%s'."), buf.buf);
+			}
+
+			if (result < 0)
+				die(_("merging cannot continue; got unclean result of %d"), result);
+			strbuf_list_free(split);
+		}
+		strbuf_release(&buf);
+		return 0;
+	}
+
+	/* Figure out which mode to use */
+	switch (o.mode) {
+	default:
+		BUG("unexpected command mode %d", o.mode);
+	case MODE_UNKNOWN:
+		switch (argc) {
+		default:
+			usage_with_options(merge_tree_usage, mt_options);
+		case 2:
+			o.mode = MODE_REAL;
+			break;
+		case 3:
+			o.mode = MODE_TRIVIAL;
+			break;
+		}
+		expected_remaining_argc = argc;
+		break;
+	case MODE_REAL:
+		expected_remaining_argc = 2;
+		break;
+	case MODE_TRIVIAL:
+		expected_remaining_argc = 3;
+		/* Removal of `--trivial-merge` is expected */
+		original_argc--;
+		break;
+	}
+	if (o.mode == MODE_TRIVIAL && argc < original_argc)
+		die(_("--trivial-merge is incompatible with all other options"));
+
+	if (argc != expected_remaining_argc)
+		usage_with_options(merge_tree_usage, mt_options);
+
+	/* Do the relevant type of merge */
+	if (o.mode == MODE_REAL)
+		return real_merge(&o, merge_base, argv[0], argv[1], prefix);
+	else
+		return trivial_merge(argv[0], argv[1], argv[2]);
+}