Make fetch a builtin

Thanks to Johannes Schindelin for review and fixes, and Julian
Phillips for the original C translation.

This changes a few small bits of behavior:

branch.<name>.merge is parsed as if it were the lhs of a fetch
refspec, and does not have to exactly match the actual lhs of a
refspec, so long as it is a valid abbreviation for the same ref.

branch.<name>.merge is no longer ignored if the remote is configured
with a branches/* file. Neither behavior is useful, because there can
only be one ref that gets fetched, but this is more consistant.

Also, fetch prints different information to standard out.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 552 insertions, 0 deletions

diff --git a/builtin-fetch.c b/builtin-fetch.c
new file mode 100644
index 000000000..64392f317
--- /dev/null
+++ b/builtin-fetch.c
@@ -0,0 +1,552 @@
+/*
+ * "git fetch"
+ */
+#include "cache.h"
+#include "refs.h"
+#include "commit.h"
+#include "builtin.h"
+#include "path-list.h"
+#include "remote.h"
+#include "transport.h"
+
+static const char fetch_usage[] = "git-fetch [-a | --append] [--upload-pack <upload-pack>] [-f | --force] [--no-tags] [-t | --tags] [-k | --keep] [-u | --update-head-ok] [--depth <depth>] [-v | --verbose] [<repository> <refspec>...]";
+
+static int append, force, tags, no_tags, update_head_ok, verbose, quiet;
+
+static int unpacklimit;
+
+static char *default_rla = NULL;
+
+static void find_merge_config(struct ref *ref_map, struct remote *remote)
+{
+	struct ref *rm = ref_map;
+	struct branch *branch = branch_get(NULL);
+
+	for (rm = ref_map; rm; rm = rm->next) {
+		if (!branch_has_merge_config(branch)) {
+			if (remote && remote->fetch &&
+			    !strcmp(remote->fetch[0].src, rm->name))
+				rm->merge = 1;
+		} else {
+			if (branch_merges(branch, rm->name))
+				rm->merge = 1;
+		}
+	}
+}
+
+static struct ref *get_ref_map(struct transport *transport,
+			       struct refspec *refs, int ref_count, int tags,
+			       int *autotags)
+{
+	int i;
+	struct ref *rm;
+	struct ref *ref_map = NULL;
+	struct ref **tail = &ref_map;
+
+	struct ref *remote_refs = transport_get_remote_refs(transport);
+
+	if (ref_count || tags) {
+		for (i = 0; i < ref_count; i++) {
+			get_fetch_map(remote_refs, &refs[i], &tail);
+			if (refs[i].dst && refs[i].dst[0])
+				*autotags = 1;
+		}
+		/* Merge everything on the command line, but not --tags */
+		for (rm = ref_map; rm; rm = rm->next)
+			rm->merge = 1;
+		if (tags) {
+			struct refspec refspec;
+			refspec.src = "refs/tags/";
+			refspec.dst = "refs/tags/";
+			refspec.pattern = 1;
+			refspec.force = 0;
+			get_fetch_map(remote_refs, &refspec, &tail);
+		}
+	} else {
+		/* Use the defaults */
+		struct remote *remote = transport->remote;
+		if (remote->fetch_refspec_nr) {
+			for (i = 0; i < remote->fetch_refspec_nr; i++) {
+				get_fetch_map(remote_refs, &remote->fetch[i], &tail);
+				if (remote->fetch[i].dst &&
+				    remote->fetch[i].dst[0])
+					*autotags = 1;
+			}
+			find_merge_config(ref_map, remote);
+		} else {
+			ref_map = get_remote_ref(remote_refs, "HEAD");
+
+			ref_map->merge = 1;
+		}
+	}
+
+	return ref_map;
+}
+
+static void show_new(enum object_type type, unsigned char *sha1_new)
+{
+	fprintf(stderr, "  %s: %s\n", typename(type),
+		find_unique_abbrev(sha1_new, DEFAULT_ABBREV));
+}
+
+static int s_update_ref(const char *action,
+			struct ref *ref,
+			int check_old)
+{
+	char msg[1024];
+	char *rla = getenv("GIT_REFLOG_ACTION");
+	static struct ref_lock *lock;
+
+	if (!rla)
+		rla = default_rla;
+	snprintf(msg, sizeof(msg), "%s: %s", rla, action);
+	lock = lock_any_ref_for_update(ref->name,
+				       check_old ? ref->old_sha1 : NULL, 0);
+	if (!lock)
+		return 1;
+	if (write_ref_sha1(lock, ref->new_sha1, msg) < 0)
+		return 1;
+	return 0;
+}
+
+static int update_local_ref(struct ref *ref,
+			    const char *note,
+			    int verbose)
+{
+	char oldh[41], newh[41];
+	struct commit *current = NULL, *updated;
+	enum object_type type;
+	struct branch *current_branch = branch_get(NULL);
+
+	type = sha1_object_info(ref->new_sha1, NULL);
+	if (type < 0)
+		die("object %s not found", sha1_to_hex(ref->new_sha1));
+
+	if (!*ref->name) {
+		/* Not storing */
+		if (verbose) {
+			fprintf(stderr, "* fetched %s\n", note);
+			show_new(type, ref->new_sha1);
+		}
+		return 0;
+	}
+
+	if (!hashcmp(ref->old_sha1, ref->new_sha1)) {
+		if (verbose) {
+			fprintf(stderr, "* %s: same as %s\n",
+				ref->name, note);
+			show_new(type, ref->new_sha1);
+		}
+		return 0;
+	}
+
+	if (!strcmp(ref->name, current_branch->name) &&
+	    !(update_head_ok || is_bare_repository()) &&
+	    !is_null_sha1(ref->old_sha1)) {
+		/*
+		 * If this is the head, and it's not okay to update
+		 * the head, and the old value of the head isn't empty...
+		 */
+		fprintf(stderr,
+			" * %s: Cannot fetch into the current branch.\n",
+			ref->name);
+		return 1;
+	}
+
+	if (!is_null_sha1(ref->old_sha1) &&
+	    !prefixcmp(ref->name, "refs/tags/")) {
+		fprintf(stderr, "* %s: updating with %s\n",
+			ref->name, note);
+		show_new(type, ref->new_sha1);
+		return s_update_ref("updating tag", ref, 0);
+	}
+
+	current = lookup_commit_reference(ref->old_sha1);
+	updated = lookup_commit_reference(ref->new_sha1);
+	if (!current || !updated) {
+		char *msg;
+		if (!strncmp(ref->name, "refs/tags/", 10))
+			msg = "storing tag";
+		else
+			msg = "storing head";
+		fprintf(stderr, "* %s: storing %s\n",
+			ref->name, note);
+		show_new(type, ref->new_sha1);
+		return s_update_ref(msg, ref, 0);
+	}
+
+	strcpy(oldh, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
+	strcpy(newh, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
+
+	if (in_merge_bases(current, &updated, 1)) {
+		fprintf(stderr, "* %s: fast forward to %s\n",
+			ref->name, note);
+		fprintf(stderr, "  old..new: %s..%s\n", oldh, newh);
+		return s_update_ref("fast forward", ref, 1);
+	}
+	if (!force && !ref->force) {
+		fprintf(stderr,
+			"* %s: not updating to non-fast forward %s\n",
+			ref->name, note);
+		fprintf(stderr,
+			"  old...new: %s...%s\n", oldh, newh);
+		return 1;
+	}
+	fprintf(stderr,
+		"* %s: forcing update to non-fast forward %s\n",
+		ref->name, note);
+	fprintf(stderr, "  old...new: %s...%s\n", oldh, newh);
+	return s_update_ref("forced-update", ref, 1);
+}
+
+static void store_updated_refs(const char *url, struct ref *ref_map)
+{
+	FILE *fp;
+	struct commit *commit;
+	int url_len, i, note_len;
+	char note[1024];
+	const char *what, *kind;
+	struct ref *rm;
+
+	fp = fopen(git_path("FETCH_HEAD"), "a");
+	for (rm = ref_map; rm; rm = rm->next) {
+		struct ref *ref = NULL;
+
+		if (rm->peer_ref) {
+			ref = xcalloc(1, sizeof(*ref) + strlen(rm->peer_ref->name) + 1);
+			strcpy(ref->name, rm->peer_ref->name);
+			hashcpy(ref->old_sha1, rm->peer_ref->old_sha1);
+			hashcpy(ref->new_sha1, rm->old_sha1);
+			ref->force = rm->force;
+		}
+
+		commit = lookup_commit_reference(rm->old_sha1);
+		if (!commit)
+			rm->merge = 0;
+
+		if (!strcmp(rm->name, "HEAD")) {
+			kind = "";
+			what = "";
+		}
+		else if (!prefixcmp(rm->name, "refs/heads/")) {
+			kind = "branch";
+			what = rm->name + 11;
+		}
+		else if (!prefixcmp(rm->name, "refs/tags/")) {
+			kind = "tag";
+			what = rm->name + 10;
+		}
+		else if (!prefixcmp(rm->name, "refs/remotes/")) {
+			kind = "remote branch";
+			what = rm->name + 13;
+		}
+		else {
+			kind = "";
+			what = rm->name;
+		}
+
+		url_len = strlen(url);
+		for (i = url_len - 1; url[i] == '/' && 0 <= i; i--)
+			;
+		url_len = i + 1;
+		if (4 < i && !strncmp(".git", url + i - 3, 4))
+			url_len = i - 3;
+
+		note_len = 0;
+		if (*what) {
+			if (*kind)
+				note_len += sprintf(note + note_len, "%s ",
+						    kind);
+			note_len += sprintf(note + note_len, "'%s' of ", what);
+		}
+		note_len += sprintf(note + note_len, "%.*s", url_len, url);
+		fprintf(fp, "%s\t%s\t%s\n",
+			sha1_to_hex(commit ? commit->object.sha1 :
+				    rm->old_sha1),
+			rm->merge ? "" : "not-for-merge",
+			note);
+
+		if (ref)
+			update_local_ref(ref, note, verbose);
+	}
+	fclose(fp);
+}
+
+static int fetch_refs(struct transport *transport, struct ref *ref_map)
+{
+	int ret = transport_fetch_refs(transport, ref_map);
+	if (!ret)
+		store_updated_refs(transport->url, ref_map);
+	return ret;
+}
+
+static int add_existing(const char *refname, const unsigned char *sha1,
+			int flag, void *cbdata)
+{
+	struct path_list *list = (struct path_list *)cbdata;
+	path_list_insert(refname, list);
+	return 0;
+}
+
+static struct ref *find_non_local_tags(struct transport *transport,
+				       struct ref *fetch_map)
+{
+	static struct path_list existing_refs = { NULL, 0, 0, 0 };
+	struct path_list new_refs = { NULL, 0, 0, 1 };
+	char *ref_name;
+	int ref_name_len;
+	unsigned char *ref_sha1;
+	struct ref *tag_ref;
+	struct ref *rm = NULL;
+	struct ref *ref_map = NULL;
+	struct ref **tail = &ref_map;
+	struct ref *ref;
+
+	for_each_ref(add_existing, &existing_refs);
+	for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
+		if (prefixcmp(ref->name, "refs/tags"))
+			continue;
+
+		ref_name = xstrdup(ref->name);
+		ref_name_len = strlen(ref_name);
+		ref_sha1 = ref->old_sha1;
+
+		if (!strcmp(ref_name + ref_name_len - 3, "^{}")) {
+			ref_name[ref_name_len - 3] = 0;
+			tag_ref = transport_get_remote_refs(transport);
+			while (tag_ref) {
+				if (!strcmp(tag_ref->name, ref_name)) {
+					ref_sha1 = tag_ref->old_sha1;
+					break;
+				}
+				tag_ref = tag_ref->next;
+			}
+		}
+
+		if (!path_list_has_path(&existing_refs, ref_name) &&
+		    !path_list_has_path(&new_refs, ref_name) &&
+		    lookup_object(ref->old_sha1)) {
+			fprintf(stderr, "Auto-following %s\n",
+				ref_name);
+
+			path_list_insert(ref_name, &new_refs);
+
+			rm = alloc_ref(strlen(ref_name) + 1);
+			strcpy(rm->name, ref_name);
+			rm->peer_ref = alloc_ref(strlen(ref_name) + 1);
+			strcpy(rm->peer_ref->name, ref_name);
+			hashcpy(rm->old_sha1, ref_sha1);
+
+			*tail = rm;
+			tail = &rm->next;
+		}
+		free(ref_name);
+	}
+
+	return ref_map;
+}
+
+static int do_fetch(struct transport *transport,
+		    struct refspec *refs, int ref_count)
+{
+	struct ref *ref_map, *fetch_map;
+	struct ref *rm;
+	int autotags = (transport->remote->fetch_tags == 1);
+	if (transport->remote->fetch_tags == 2 && !no_tags)
+		tags = 1;
+	if (transport->remote->fetch_tags == -1)
+		no_tags = 1;
+
+	if (!transport->ops || !transport->ops->get_refs_list ||
+	    !(transport->ops->fetch_refs || transport->ops->fetch_objs))
+		die("Don't know how to fetch from %s", transport->url);
+
+	/* if not appending, truncate FETCH_HEAD */
+	if (!append)
+		fclose(fopen(git_path("FETCH_HEAD"), "w"));
+
+	ref_map = get_ref_map(transport, refs, ref_count, tags, &autotags);
+
+	for (rm = ref_map; rm; rm = rm->next) {
+		if (rm->peer_ref)
+			read_ref(rm->peer_ref->name, rm->peer_ref->old_sha1);
+
+		printf("%s : %s\n", rm->name, rm->peer_ref ? rm->peer_ref->name : NULL);
+		printf("  < %s\n", sha1_to_hex(rm->old_sha1));
+		if (rm->peer_ref)
+			printf("  > %s\n", sha1_to_hex(rm->peer_ref->old_sha1));
+		if (!rm->peer_ref ||
+		    hashcmp(rm->old_sha1, rm->peer_ref->old_sha1)) {
+			printf("%s needs update.\n", rm->name);
+		}
+	}
+
+	if (fetch_refs(transport, ref_map)) {
+		free_refs(ref_map);
+		return 1;
+	}
+
+	fetch_map = ref_map;
+
+	/* if neither --no-tags nor --tags was specified, do automated tag
+	 * following ... */
+	if (!(tags || no_tags) && autotags) {
+		ref_map = find_non_local_tags(transport, fetch_map);
+		if (ref_map) {
+			transport_set_option(transport, TRANS_OPT_DEPTH, "0");
+			fetch_refs(transport, ref_map);
+		}
+		free_refs(ref_map);
+	}
+
+	free_refs(fetch_map);
+
+	return 0;
+}
+
+static int fetch_config(const char *var, const char *value)
+{
+	if (strcmp(var, "fetch.unpacklimit") == 0) {
+		unpacklimit = git_config_int(var, value);
+		return 0;
+	}
+
+	if (strcmp(var, "transfer.unpacklimit") == 0) {
+		unpacklimit = git_config_int(var, value);
+		return 0;
+	}
+
+	return git_default_config(var, value);
+}
+
+int cmd_fetch(int argc, const char **argv, const char *prefix)
+{
+	struct remote *remote;
+	struct transport *transport;
+	int i, j, rla_offset;
+	static const char **refs = NULL;
+	int ref_nr = 0;
+	int cmd_len = 0;
+	const char *depth = NULL, *upload_pack = NULL;
+	int keep = 0;
+
+	git_config(fetch_config);
+
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+		cmd_len += strlen(arg);
+
+		if (arg[0] != '-')
+			break;
+		if (!strcmp(arg, "--append") || !strcmp(arg, "-a")) {
+			append = 1;
+			continue;
+		}
+		if (!prefixcmp(arg, "--upload-pack=")) {
+			upload_pack = arg + 14;
+			continue;
+		}
+		if (!strcmp(arg, "--upload-pack")) {
+			i++;
+			if (i == argc)
+				usage(fetch_usage);
+			upload_pack = argv[i];
+			continue;
+		}
+		if (!strcmp(arg, "--force") || !strcmp(arg, "-f")) {
+			force = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--no-tags")) {
+			no_tags = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--tags") || !strcmp(arg, "-t")) {
+			tags = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--keep") || !strcmp(arg, "-k")) {
+			keep = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--update-head-ok") || !strcmp(arg, "-u")) {
+			update_head_ok = 1;
+			continue;
+		}
+		if (!prefixcmp(arg, "--depth=")) {
+			depth = arg + 8;
+			continue;
+		}
+		if (!strcmp(arg, "--depth")) {
+			i++;
+			if (i == argc)
+				usage(fetch_usage);
+			depth = argv[i];
+			continue;
+		}
+		if (!strcmp(arg, "--quiet")) {
+			quiet = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--verbose") || !strcmp(arg, "-v")) {
+			verbose++;
+			continue;
+		}
+		usage(fetch_usage);
+	}
+
+	for (j = i; j < argc; j++)
+		cmd_len += strlen(argv[j]);
+
+	default_rla = xmalloc(cmd_len + 5 + argc + 1);
+	sprintf(default_rla, "fetch");
+	rla_offset = strlen(default_rla);
+	for (j = 1; j < argc; j++) {
+		sprintf(default_rla + rla_offset, " %s", argv[j]);
+		rla_offset += strlen(argv[j]);
+	}
+
+	if (i == argc)
+		remote = remote_get(NULL);
+	else
+		remote = remote_get(argv[i++]);
+
+	transport = transport_get(remote, remote->uri[0], 1);
+	if (verbose >= 2)
+		transport->verbose = 1;
+	if (quiet)
+		transport->verbose = 0;
+	if (upload_pack)
+		transport_set_option(transport, TRANS_OPT_UPLOADPACK, upload_pack);
+	if (keep)
+		transport_set_option(transport, TRANS_OPT_KEEP, "yes");
+	transport_set_option(transport, TRANS_OPT_DEPTH, depth);
+
+	if (!transport->url)
+		die("Where do you want to fetch from today?");
+
+	if (i < argc) {
+		int j = 0;
+		refs = xcalloc(argc - i + 1, sizeof(const char *));
+		while (i < argc) {
+			if (!strcmp(argv[i], "tag")) {
+				char *ref;
+				i++;
+				ref = xmalloc(strlen(argv[i]) * 2 + 22);
+				strcpy(ref, "refs/tags/");
+				strcat(ref, argv[i]);
+				strcat(ref, ":refs/tags/");
+				strcat(ref, argv[i]);
+				refs[j++] = ref;
+			} else
+				refs[j++] = argv[i];
+			i++;
+		}
+		refs[j] = NULL;
+		ref_nr = j;
+		for (j = 0; refs[j]; j++)
+			printf("ref: %s\n", refs[j]);
+	}
+
+	return do_fetch(transport, parse_ref_spec(ref_nr, refs), ref_nr);
+}