git-svn: Send deltas during commits
[gitweb.git] / builtin-checkout.c
index fbd5105a8302a6c00e191ef49f3dfef1fc979c53..efdb1e02bf21fb3b901d375a547d7fbf44e0894b 100644 (file)
@@ -157,7 +157,7 @@ struct checkout_opts {
        int force;
        int writeout_error;
 
-       char *new_branch;
+       const char *new_branch;
        int new_branch_log;
        enum branch_track track;
 };
@@ -386,13 +386,11 @@ 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) {
@@ -430,20 +428,81 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
                OPT_BOOLEAN('m', NULL, &opts.merge, "merge"),
                OPT_END(),
        };
+       int has_dash_dash;
 
        memset(&opts, 0, sizeof(opts));
        memset(&new, 0, sizeof(new));
 
        git_config(git_default_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 (opts.force && opts.merge)
+               die("git checkout: -f and -m are incompatible");
 
-       argc = parse_options(argc, argv, options, checkout_usage, 0);
+       /*
+        * case 1: git checkout <ref> -- [<paths>]
+        *
+        *   <ref> must be a valid tree, everything after the '--' must be
+        *   a path.
+        *
+        * case 2: git checkout -- [<paths>]
+        *
+        *   everything after the '--' must be paths.
+        *
+        * case 3: git checkout <something> [<paths>]
+        *
+        *   With no paths, if <something> is a commit, that is to
+        *   switch to the branch or detach HEAD at it.
+        *
+        *   Otherwise <something> shall not be ambiguous.
+        *   - If it's *only* a reference, treat it like case (1).
+        *   - If it's only a path, treat it like case (2).
+        *   - else: fail.
+        *
+        */
        if (argc) {
+               if (!strcmp(argv[0], "--")) {       /* case (2) */
+                       argv++;
+                       argc--;
+                       goto no_reference;
+               }
+
                arg = argv[0];
-               if (get_sha1(arg, rev))
-                       ;
-               else if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
+               has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
+
+               if (get_sha1(arg, rev)) {
+                       if (has_dash_dash)          /* case (1) */
+                               die("invalid reference: %s", arg);
+                       goto no_reference;          /* case (3 -> 2) */
+               }
+
+               /* we can't end up being in (2) anymore, eat the argument */
+               argv++;
+               argc--;
+
+               if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
                        new.name = arg;
                        setup_branch_path(&new);
                        if (resolve_ref(new.path, rev, 1, NULL))
@@ -452,25 +511,28 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
                                new.path = NULL;
                        parse_commit(new.commit);
                        source_tree = new.commit->tree;
-                       argv++;
-                       argc--;
-               } else if ((source_tree = parse_tree_indirect(rev))) {
+               } else
+                       source_tree = parse_tree_indirect(rev);
+
+               if (!source_tree)                   /* case (1): want a tree */
+                       die("reference is not a tree: %s", arg);
+               if (!has_dash_dash) {/* case (3 -> 1) */
+                       /*
+                        * Do not complain the most common case
+                        *      git checkout branch
+                        * even if there happen to be a file called 'branch';
+                        * it would be extremely annoying.
+                        */
+                       if (argc)
+                               verify_non_filename(NULL, arg);
+               }
+               else {
                        argv++;
                        argc--;
                }
        }
 
-       if (argc && !strcmp(argv[0], "--")) {
-               argv++;
-               argc--;
-       }
-
-       if (!opts.new_branch && (opts.track != git_branch_track))
-               die("git checkout: --track and --no-track require -b");
-
-       if (opts.force && opts.merge)
-               die("git checkout: -f and -m are incompatible");
-
+no_reference:
        if (argc) {
                const char **pathspec = get_pathspec(prefix, argv);