git checkout -b: allow switching out of an unborn branch

[git.git] / builtin / checkout.c

diff --git a/builtin/checkout.c b/builtin/checkout.c
index ca855d716ccab1d1209638193e2f52e901acfba0..b76e2c0451cbeb73e1fd227c343413b1c8a33cc7 100644 (file)
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -201,7 +201,7 @@ static int checkout_merged(int pos, struct checkout *state)
 }
 
 static int checkout_paths(struct tree *source_tree, const char **pathspec,
-                         struct checkout_opts *opts)
+                         const char *prefix, struct checkout_opts *opts)
 {
        int pos;
        struct checkout state;
@@ -231,7 +231,7 @@ static int checkout_paths(struct tree *source_tree, const char **pathspec,
                match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, ps_matched);
        }
 
-       if (report_path_error(ps_matched, pathspec, 0))
+       if (report_path_error(ps_matched, pathspec, prefix))
                return 1;
 
        /* "checkout -m path" to recreate conflicted state */
@@ -916,6 +916,17 @@ static int parse_branchname_arg(int argc, const char **argv,
        return argcount;
 }
 
+static int switch_unborn_to_new_branch(struct checkout_opts *opts)
+{
+       int status;
+       struct strbuf branch_ref = STRBUF_INIT;
+
+       strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
+       status = create_symref("HEAD", branch_ref.buf, "checkout -b");
+       strbuf_release(&branch_ref);
+       return status;
+}
+
 int cmd_checkout(int argc, const char **argv, const char *prefix)
 {
        struct checkout_opts opts;
@@ -1063,7 +1074,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
                if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
                        die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\nchecking out of the index."));
 
-               return checkout_paths(source_tree, pathspec, &opts);
+               return checkout_paths(source_tree, pathspec, prefix, &opts);
        }
 
        if (patch_mode)
@@ -1089,5 +1100,13 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
        if (opts.writeout_stage)
                die(_("--ours/--theirs is incompatible with switching branches."));
 
+       if (!new.commit) {
+               unsigned char rev[20];
+               int flag;
+
+               resolve_ref("HEAD", rev, 0, &flag);
+               if ((flag & REF_ISSYMREF) && is_null_sha1(rev))
+                       return switch_unborn_to_new_branch(&opts);
+       }
        return switch_branches(&opts, &new);
 }