Merge branch 'jc/better-conflict-resolution'

[git.git] / builtin-checkout.c

diff --git a/builtin-checkout.c b/builtin-checkout.c
index 79214327b0d99369b3ce384ed1900342f5874c87..b572b3bf69c791912717eae313942316cd77ac37 100644 (file)
--- a/builtin-checkout.c
+++ b/builtin-checkout.c
@@ -397,6 +397,8 @@ static int merge_working_tree(struct checkout_opts *opts,
                }
 
                /* 2-way merge to the new branch */
+               topts.initial_checkout = (!active_nr &&
+                                         (old->commit == new->commit));
                topts.update = 1;
                topts.merge = 1;
                topts.gently = opts->merge;
@@ -419,6 +421,7 @@ static int merge_working_tree(struct checkout_opts *opts,
                         */
                        struct tree *result;
                        struct tree *work;
+                       struct merge_options o;
                        if (!opts->merge)
                                return 1;
                        parse_commit(old->commit);
@@ -437,13 +440,17 @@ static int merge_working_tree(struct checkout_opts *opts,
                         */
 
                        add_files_to_cache(NULL, NULL, 0);
-                       work = write_tree_from_memory();
+                       init_merge_options(&o);
+                       o.verbosity = 0;
+                       work = write_tree_from_memory(&o);
 
                        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);
+                       o.branch1 = new->name;
+                       o.branch2 = "local";
+                       merge_trees(&o, new->commit->tree, work,
+                               old->commit->tree, &result);
                        ret = reset_tree(new->commit->tree, opts, 0);
                        if (ret)
                                return ret;
@@ -454,7 +461,7 @@ static int merge_working_tree(struct checkout_opts *opts,
            commit_locked_index(lock_file))
                die("unable to write new index file");
 
-       if (!opts->force)
+       if (!opts->force && !opts->quiet)
                show_local_changes(&new->commit->object);
 
        return 0;
@@ -541,13 +548,11 @@ static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
        }
 
        /*
-        * If the new thing isn't a branch and isn't HEAD and we're
-        * not starting a new branch, and we want messages, and we
-        * weren't on a branch, and we're moving to a new commit,
-        * describe the old commit.
+        * If we were on a detached HEAD, but we are now moving to
+        * a new commit, we want to mention the old commit once more
+        * to remind the user that it might be lost.
         */
-       if (!new->path && strcmp(new->name, "HEAD") && !opts->new_branch &&
-           !opts->quiet && !old.path && new->commit != old.commit)
+       if (!opts->quiet && !old.path && new->commit != old.commit)
                describe_detached_head("Previous HEAD position was", old.commit);
 
        if (!old.commit) {
@@ -604,11 +609,28 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 
        git_config(git_checkout_config, NULL);
 
-       opts.track = git_branch_track;
+       opts.track = BRANCH_TRACK_UNSPECIFIED;
 
        argc = parse_options(argc, argv, options, checkout_usage,
                             PARSE_OPT_KEEP_DASHDASH);
 
+       /* --track without -b should DWIM */
+       if (0 < opts.track && !opts.new_branch) {
+               const char *argv0 = argv[0];
+               if (!argc || !strcmp(argv0, "--"))
+                       die ("--track needs a branch name");
+               if (!prefixcmp(argv0, "refs/"))
+                       argv0 += 5;
+               if (!prefixcmp(argv0, "remotes/"))
+                       argv0 += 8;
+               argv0 = strchr(argv0, '/');
+               if (!argv0 || !argv0[1])
+                       die ("Missing branch name; try -b");
+               opts.new_branch = argv0 + 1;
+       }
+
+       if (opts.track == BRANCH_TRACK_UNSPECIFIED)
+               opts.track = git_branch_track;
        if (conflict_style) {
                opts.merge = 1; /* implied */
                git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
@@ -713,6 +735,18 @@ no_reference:
                return checkout_paths(source_tree, pathspec, &opts);
        }
 
+       if (opts.new_branch) {
+               struct strbuf buf;
+               strbuf_init(&buf, 0);
+               strbuf_addstr(&buf, "refs/heads/");
+               strbuf_addstr(&buf, opts.new_branch);
+               if (!get_sha1(buf.buf, rev))
+                       die("git checkout: branch %s already exists", opts.new_branch);
+               if (check_ref_format(buf.buf))
+                       die("git checkout: we do not like '%s' as a branch name.", opts.new_branch);
+               strbuf_release(&buf);
+       }
+
        if (new.name && !new.commit) {
                die("Cannot switch branch to a non-commit.");
        }