GIT-VERSION-GEN: do not fail if a 'HEAD' file exists in the working copy
[gitweb.git] / builtin-checkout.c
index 0d19835a6b9e8d52574531c0453eff91f47b8e8d..93ea69bfaa083f49a6e808c7317ea1910b29c847 100644 (file)
@@ -67,17 +67,8 @@ static int update_some(const unsigned char *sha1, const char *base, int baselen,
 
 static int read_tree_some(struct tree *tree, const char **pathspec)
 {
-       int newfd;
-       struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
-       newfd = hold_locked_index(lock_file, 1);
-       read_cache();
-
        read_tree_recursive(tree, "", 0, 0, pathspec, update_some);
 
-       if (write_cache(newfd, active_cache, active_nr) ||
-           commit_locked_index(lock_file))
-               die("unable to write new index file");
-
        /* update the index with the given tree's info
         * for all args, expanding wildcards, and exit
         * with any non-zero return code.
@@ -85,7 +76,7 @@ static int read_tree_some(struct tree *tree, const char **pathspec)
        return 0;
 }
 
-static int checkout_paths(const char **pathspec)
+static int checkout_paths(struct tree *source_tree, const char **pathspec)
 {
        int pos;
        struct checkout state;
@@ -93,6 +84,16 @@ static int checkout_paths(const char **pathspec)
        unsigned char rev[20];
        int flag;
        struct commit *head;
+       int errs = 0;
+
+       int newfd;
+       struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
+
+       newfd = hold_locked_index(lock_file, 1);
+       read_cache();
+
+       if (source_tree)
+               read_tree_some(source_tree, pathspec);
 
        for (pos = 0; pathspec[pos]; pos++)
                ;
@@ -106,20 +107,26 @@ static int checkout_paths(const char **pathspec)
        if (report_path_error(ps_matched, pathspec, 0))
                return 1;
 
+       /* Now we are committed to check them out */
        memset(&state, 0, sizeof(state));
        state.force = 1;
        state.refresh_cache = 1;
        for (pos = 0; pos < active_nr; pos++) {
                struct cache_entry *ce = active_cache[pos];
                if (pathspec_match(pathspec, NULL, ce->name, 0)) {
-                       checkout_entry(ce, &state, NULL);
+                       errs |= checkout_entry(ce, &state, NULL);
                }
        }
 
+       if (write_cache(newfd, active_cache, active_nr) ||
+           commit_locked_index(lock_file))
+               die("unable to write new index file");
+
        resolve_ref("HEAD", rev, 0, &flag);
        head = lookup_commit_reference_gently(rev, 1);
 
-       return post_checkout_hook(head, head, 0);
+       errs |= post_checkout_hook(head, head, 0);
+       return errs;
 }
 
 static void show_local_changes(struct object *head)
@@ -138,57 +145,56 @@ static void describe_detached_head(char *msg, struct commit *commit)
        struct strbuf sb;
        strbuf_init(&sb, 0);
        parse_commit(commit);
-       pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, 0, "", "", 0, 0);
+       pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, 0, NULL, NULL, 0, 0);
        fprintf(stderr, "%s %s... %s\n", msg,
                find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
        strbuf_release(&sb);
 }
 
-static int reset_to_new(struct tree *tree, int quiet)
-{
-       struct unpack_trees_options opts;
-       struct tree_desc tree_desc;
-       memset(&opts, 0, sizeof(opts));
-       opts.head_idx = -1;
-       opts.update = 1;
-       opts.reset = 1;
-       opts.merge = 1;
-       opts.fn = oneway_merge;
-       opts.verbose_update = !quiet;
-       parse_tree(tree);
-       init_tree_desc(&tree_desc, tree->buffer, tree->size);
-       if (unpack_trees(1, &tree_desc, &opts))
-               return 128;
-       return 0;
-}
+struct checkout_opts {
+       int quiet;
+       int merge;
+       int force;
+       int writeout_error;
 
-static void reset_clean_to_new(struct tree *tree, int quiet)
+       char *new_branch;
+       int new_branch_log;
+       enum branch_track track;
+};
+
+static int reset_tree(struct tree *tree, struct checkout_opts *o, int worktree)
 {
        struct unpack_trees_options opts;
        struct tree_desc tree_desc;
+
        memset(&opts, 0, sizeof(opts));
        opts.head_idx = -1;
-       opts.skip_unmerged = 1;
+       opts.update = worktree;
+       opts.skip_unmerged = !worktree;
        opts.reset = 1;
        opts.merge = 1;
        opts.fn = oneway_merge;
-       opts.verbose_update = !quiet;
+       opts.verbose_update = !o->quiet;
+       opts.src_index = &the_index;
+       opts.dst_index = &the_index;
        parse_tree(tree);
        init_tree_desc(&tree_desc, tree->buffer, tree->size);
-       if (unpack_trees(1, &tree_desc, &opts))
-               exit(128);
+       switch (unpack_trees(1, &tree_desc, &opts)) {
+       case -2:
+               o->writeout_error = 1;
+               /*
+                * We return 0 nevertheless, as the index is all right
+                * and more importantly we have made best efforts to
+                * update paths in the work tree, and we cannot revert
+                * them.
+                */
+       case 0:
+               return 0;
+       default:
+               return 128;
+       }
 }
 
-struct checkout_opts {
-       int quiet;
-       int merge;
-       int force;
-
-       char *new_branch;
-       int new_branch_log;
-       int track;
-};
-
 struct branch_info {
        const char *name; /* The short name used */
        const char *path; /* The full name of a real branch */
@@ -205,8 +211,7 @@ static void setup_branch_path(struct branch_info *branch)
 }
 
 static int merge_working_tree(struct checkout_opts *opts,
-                             struct branch_info *old, struct branch_info *new,
-                             const char *prefix)
+                             struct branch_info *old, struct branch_info *new)
 {
        int ret;
        struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
@@ -214,37 +219,44 @@ static int merge_working_tree(struct checkout_opts *opts,
        read_cache();
 
        if (opts->force) {
-               ret = reset_to_new(new->commit->tree, opts->quiet);
+               ret = reset_tree(new->commit->tree, opts, 1);
                if (ret)
                        return ret;
        } else {
                struct tree_desc trees[2];
                struct tree *tree;
                struct unpack_trees_options topts;
+
                memset(&topts, 0, sizeof(topts));
                topts.head_idx = -1;
+               topts.src_index = &the_index;
+               topts.dst_index = &the_index;
+
+               topts.msgs.not_uptodate_file = "You have local changes to '%s'; cannot switch branches.";
 
                refresh_cache(REFRESH_QUIET);
 
                if (unmerged_cache()) {
-                       ret = opts->merge ? -1 :
-                               error("you need to resolve your current index first");
-               } else {
-                       topts.update = 1;
-                       topts.merge = 1;
-                       topts.gently = opts->merge;
-                       topts.fn = twoway_merge;
-                       topts.dir = xcalloc(1, sizeof(*topts.dir));
-                       topts.dir->show_ignored = 1;
-                       topts.dir->exclude_per_dir = ".gitignore";
-                       topts.prefix = prefix;
-                       tree = parse_tree_indirect(old->commit->object.sha1);
-                       init_tree_desc(&trees[0], tree->buffer, tree->size);
-                       tree = parse_tree_indirect(new->commit->object.sha1);
-                       init_tree_desc(&trees[1], tree->buffer, tree->size);
-                       ret = unpack_trees(2, trees, &topts);
+                       error("you need to resolve your current index first");
+                       return 1;
                }
-               if (ret) {
+
+               /* 2-way merge to the new branch */
+               topts.update = 1;
+               topts.merge = 1;
+               topts.gently = opts->merge;
+               topts.verbose_update = !opts->quiet;
+               topts.fn = twoway_merge;
+               topts.dir = xcalloc(1, sizeof(*topts.dir));
+               topts.dir->show_ignored = 1;
+               topts.dir->exclude_per_dir = ".gitignore";
+               tree = parse_tree_indirect(old->commit->object.sha1);
+               init_tree_desc(&trees[0], tree->buffer, tree->size);
+               tree = parse_tree_indirect(new->commit->object.sha1);
+               init_tree_desc(&trees[1], tree->buffer, tree->size);
+
+               ret = unpack_trees(2, trees, &topts);
+               if (ret == -1) {
                        /*
                         * Unpack couldn't do a trivial merge; either
                         * give up or do a real merge, depending on
@@ -269,15 +281,17 @@ static int merge_working_tree(struct checkout_opts *opts,
                         * entries in the index.
                         */
 
-                       add_files_to_cache(0, NULL, NULL);
+                       add_files_to_cache(NULL, NULL, 0);
                        work = write_tree_from_memory();
 
-                       ret = reset_to_new(new->commit->tree, opts->quiet);
+                       ret = reset_tree(new->commit->tree, opts, 1);
                        if (ret)
                                return ret;
                        merge_trees(new->commit->tree, work, old->commit->tree,
                                    new->name, "local", &result);
-                       reset_clean_to_new(new->commit->tree, opts->quiet);
+                       ret = reset_tree(new->commit->tree, opts, 0);
+                       if (ret)
+                               return ret;
                }
        }
 
@@ -291,72 +305,7 @@ static int merge_working_tree(struct checkout_opts *opts,
        return 0;
 }
 
-/*
- * We really should allow cb_data... Yuck
- */
-static const char *branch_name;
-static int branch_name_len;
-static char *found_remote;
-static char *found_merge;
-static int read_branch_config(const char *var, const char *value)
-{
-       const char *name;
-       if (prefixcmp(var, "branch."))
-               return 0; /* not ours */
-       name = var + strlen("branch.");
-       if (strncmp(name, branch_name, branch_name_len) ||
-           name[branch_name_len] != '.')
-               return 0; /* not ours either */
-       if (!strcmp(name + branch_name_len, ".remote")) {
-               /*
-                * Yeah, I know Christian's clean-up should
-                * be used here, but the topic is based on an
-                * older fork point.
-                */
-               if (!value)
-                       return error("'%s' not string", var);
-               found_remote = xstrdup(value);
-               return 0;
-       }
-       if (!strcmp(name + branch_name_len, ".merge")) {
-               if (!value)
-                       return error("'%s' not string", var);
-               found_merge = xstrdup(value);
-               return 0;
-       }
-       return 0; /* not ours */
-}
-
-static int find_build_base(const char *ours, char **base)
-{
-       struct remote *remote;
-       struct refspec spec;
-
-       *base = NULL;
-
-       branch_name = ours + strlen("refs/heads/");
-       branch_name_len = strlen(branch_name);
-       found_remote = NULL;
-       found_merge = NULL;
-       git_config(read_branch_config);
-
-       if (!found_remote || !found_merge) {
-       cleanup:
-               free(found_remote);
-               free(found_merge);
-               return 0;
-       }
-
-       remote = remote_get(found_remote);
-       memset(&spec, 0, sizeof(spec));
-       spec.src = found_merge;
-       if (remote_find_tracking(remote, &spec))
-               goto cleanup;
-       *base = spec.dst;
-       return 1;
-}
-
-static void adjust_to_tracking(struct branch_info *new, struct checkout_opts *opts)
+static void report_tracking(struct branch_info *new, struct checkout_opts *opts)
 {
        /*
         * We have switched to a new branch; is it building on
@@ -366,63 +315,88 @@ static void adjust_to_tracking(struct branch_info *new, struct checkout_opts *op
        char *base;
        unsigned char sha1[20];
        struct commit *ours, *theirs;
-       const char *msgfmt;
        char symmetric[84];
-       int show_log;
+       struct rev_info revs;
+       const char *rev_argv[10];
+       int rev_argc;
+       int num_ours, num_theirs;
+       const char *remote_msg;
+       struct branch *branch = branch_get(new->name);
 
-       if (!resolve_ref(new->path, sha1, 1, NULL))
-               return;
-       ours = lookup_commit(sha1);
-
-       if (!find_build_base(new->path, &base))
+       /*
+        * Nothing to report unless we are marked to build on top of
+        * somebody else.
+        */
+       if (!branch || !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
                return;
 
-       sprintf(symmetric, "%s", sha1_to_hex(sha1));
-
        /*
-        * Ok, it is tracking base; is it ahead of us?
+        * If what we used to build on no longer exists, there is
+        * nothing to report.
         */
+       base = branch->merge[0]->dst;
        if (!resolve_ref(base, sha1, 1, NULL))
                return;
-       theirs = lookup_commit(sha1);
-
-       sprintf(symmetric + 40, "...%s", sha1_to_hex(sha1));
 
+       theirs = lookup_commit(sha1);
+       ours = new->commit;
        if (!hashcmp(sha1, ours->object.sha1))
                return; /* we are the same */
 
-       show_log = 1;
-       if (in_merge_bases(theirs, &ours, 1)) {
-               msgfmt = "You are ahead of the tracked branch '%s'\n";
-               show_log = 0;
+       /* Run "rev-list --left-right ours...theirs" internally... */
+       rev_argc = 0;
+       rev_argv[rev_argc++] = NULL;
+       rev_argv[rev_argc++] = "--left-right";
+       rev_argv[rev_argc++] = symmetric;
+       rev_argv[rev_argc++] = "--";
+       rev_argv[rev_argc] = NULL;
+
+       strcpy(symmetric, sha1_to_hex(ours->object.sha1));
+       strcpy(symmetric + 40, "...");
+       strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
+
+       init_revisions(&revs, NULL);
+       setup_revisions(rev_argc, rev_argv, &revs, NULL);
+       prepare_revision_walk(&revs);
+
+       /* ... and count the commits on each side. */
+       num_ours = 0;
+       num_theirs = 0;
+       while (1) {
+               struct commit *c = get_revision(&revs);
+               if (!c)
+                       break;
+               if (c->object.flags & SYMMETRIC_LEFT)
+                       num_ours++;
+               else
+                       num_theirs++;
        }
-       else if (in_merge_bases(ours, &theirs, 1))
-               msgfmt = "Your branch can be fast-forwarded to the tracked branch '%s'\n";
-       else
-               msgfmt = "Both your branch and the tracked branch '%s' have own changes, you would eventually need to merge\n";
 
-       if (!prefixcmp(base, "refs/remotes/"))
+       if (!prefixcmp(base, "refs/remotes/")) {
+               remote_msg = " remote";
                base += strlen("refs/remotes/");
-       fprintf(stderr, msgfmt, base);
-
-       if (show_log) {
-               const char *args[32];
-               int ac;
-
-               ac = 0;
-               args[ac++] = "log";
-               args[ac++] = "--pretty=oneline";
-               args[ac++] = "--abbrev-commit";
-               args[ac++] = "--left-right";
-               args[ac++] = "--boundary";
-               args[ac++] = symmetric;
-               args[ac++] = "--";
-               args[ac] = NULL;
-
-               run_command_v_opt(args, RUN_GIT_CMD);
+       } else {
+               remote_msg = "";
        }
-}
 
+       if (!num_theirs)
+               printf("Your branch is ahead of the tracked%s branch '%s' "
+                      "by %d commit%s.\n",
+                      remote_msg, base,
+                      num_ours, (num_ours == 1) ? "" : "s");
+       else if (!num_ours)
+               printf("Your branch is behind the tracked%s branch '%s' "
+                      "by %d commit%s,\n"
+                      "and can be fast-forwarded.\n",
+                      remote_msg, base,
+                      num_theirs, (num_theirs == 1) ? "" : "s");
+       else
+               printf("Your branch and the tracked%s branch '%s' "
+                      "have diverged,\nand respectively "
+                      "have %d and %d different commit(s) each.\n",
+                      remote_msg, base,
+                      num_ours, num_theirs);
+}
 
 static void update_refs_for_switch(struct checkout_opts *opts,
                                   struct branch_info *old,
@@ -466,12 +440,11 @@ static void update_refs_for_switch(struct checkout_opts *opts,
        }
        remove_branch_state();
        strbuf_release(&msg);
-       if (new->path)
-               adjust_to_tracking(new, opts);
+       if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
+               report_tracking(new, opts);
 }
 
-static int switch_branches(struct checkout_opts *opts,
-                          struct branch_info *new, const char *prefix)
+static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
 {
        int ret = 0;
        struct branch_info old;
@@ -512,23 +485,14 @@ static int switch_branches(struct checkout_opts *opts,
                opts->force = 1;
        }
 
-       ret = merge_working_tree(opts, &old, new, prefix);
+       ret = merge_working_tree(opts, &old, new);
        if (ret)
                return ret;
 
        update_refs_for_switch(opts, &old, new);
 
-       return post_checkout_hook(old.commit, new->commit, 1);
-}
-
-static int branch_track = 0;
-
-static int git_checkout_config(const char *var, const char *value)
-{
-       if (!strcmp(var, "branch.autosetupmerge"))
-               branch_track = git_config_bool(var, value);
-
-       return git_default_config(var, value);
+       ret = post_checkout_hook(old.commit, new->commit, 1);
+       return ret || opts->writeout_error;
 }
 
 int cmd_checkout(int argc, const char **argv, const char *prefix)
@@ -542,7 +506,8 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
                OPT__QUIET(&opts.quiet),
                OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
                OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
-               OPT_BOOLEAN( 0 , "track", &opts.track, "track"),
+               OPT_SET_INT('t', "track",  &opts.track, "track",
+                       BRANCH_TRACK_EXPLICIT),
                OPT_BOOLEAN('f', NULL, &opts.force, "force"),
                OPT_BOOLEAN('m', NULL, &opts.merge, "merge"),
                OPT_END(),
@@ -551,9 +516,9 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
        memset(&opts, 0, sizeof(opts));
        memset(&new, 0, sizeof(new));
 
-       git_config(git_checkout_config);
+       git_config(git_default_config, NULL);
 
-       opts.track = branch_track;
+       opts.track = git_branch_track;
 
        argc = parse_options(argc, argv, options, checkout_usage, 0);
        if (argc) {
@@ -582,7 +547,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
                argc--;
        }
 
-       if (!opts.new_branch && (opts.track != branch_track))
+       if (!opts.new_branch && (opts.track != git_branch_track))
                die("git checkout: --track and --no-track require -b");
 
        if (opts.force && opts.merge)
@@ -590,6 +555,10 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 
        if (argc) {
                const char **pathspec = get_pathspec(prefix, argv);
+
+               if (!pathspec)
+                       die("invalid path specification");
+
                /* Checkout paths */
                if (opts.new_branch || opts.force || opts.merge) {
                        if (argc == 1) {
@@ -599,16 +568,12 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
                        }
                }
 
-               if (source_tree)
-                       read_tree_some(source_tree, pathspec);
-               else
-                       read_cache();
-               return checkout_paths(pathspec);
+               return checkout_paths(source_tree, pathspec);
        }
 
        if (new.name && !new.commit) {
                die("Cannot switch branch to a non-commit.");
        }
 
-       return switch_branches(&opts, &new, prefix);
+       return switch_branches(&opts, &new);
 }