show-branch: --current includes the current branch.

With this, the command includes the current branch to the list
of revs to be shown when it is not given on the command line.
This is handy to use in the configuration file like this:

	[showbranch]
	default = --current
	default = heads/*	; primary branches, not topics under
				; subdirectories

Signed-off-by: Junio C Hamano <junkio@cox.net>

2 files changed, 46 insertions, 16 deletions

diff --git a/Documentation/git-show-branch.txt b/Documentation/git-show-branch.txt
index 4bef4767e0..7b1a9c9875 100644
--- a/Documentation/git-show-branch.txt
+++ b/Documentation/git-show-branch.txt
@@ -7,7 +7,10 @@ git-show-branch - Show branches and their commits.
 
 SYNOPSIS
 --------
-'git-show-branch [--all] [--heads] [--tags] [--topo-order] [--more=<n> | --list | --independent | --merge-base] [--no-name | --sha1-name] [<rev> | <glob>]...'
+[verse]
+git-show-branch [--all] [--heads] [--tags] [--topo-order] [--current]
+	[--more=<n> | --list | --independent | --merge-base]
+	[--no-name | --sha1-name] [<rev> | <glob>]...
 
 DESCRIPTION
 -----------
@@ -38,6 +41,11 @@ OPTIONS
 	Show all refs under $GIT_DIR/refs, $GIT_DIR/refs/heads,
 	and $GIT_DIR/refs/tags, respectively.
 
+--current::
+	With this option, the command includes the current
+	branch to the list of revs to be shown when it is not
+	given on the command line.
+
 --topo-order::
         By default, the branches and their commits are shown in
         reverse chronological order.  This option makes them
@@ -134,7 +142,8 @@ it, having the following in the configuration file may help:
 ------------
 
 With this,`git show-branch` without extra parameters would show
-only the primary branches.
+only the primary branches.  In addition, if you happen to be on
+your topic branch, it is shown as well.
 
 
 
diff --git a/show-branch.c b/show-branch.c
index ea3d9e4c84..7a0dcc649e 100644
--- a/show-branch.c
+++ b/show-branch.c
@@ -5,7 +5,7 @@
 #include "refs.h"
 
 static const char show_branch_usage[] =
-"git-show-branch [--all] [--heads] [--tags] [--topo-order] [--more=count | --list | --independent | --merge-base ] [<refs>...]";
+"git-show-branch [--current] [--all] [--heads] [--tags] [--topo-order] [--more=count | --list | --independent | --merge-base ] [<refs>...]";
 
 static int default_num = 0;
 static int default_alloc = 0;
@@ -435,12 +435,12 @@ static void snarf_refs(int head, int tag)
 	}
 }
 
-static int rev_is_head(char *head_path, int headlen,
-		       char *name,
+static int rev_is_head(char *head_path, int headlen, char *name,
 		       unsigned char *head_sha1, unsigned char *sha1)
 {
 	int namelen;
-	if ((!head_path[0]) || memcmp(head_sha1, sha1, 20))
+	if ((!head_path[0]) ||
+	    (head_sha1 && sha1 && memcmp(head_sha1, sha1, 20)))
 		return 0;
 	namelen = strlen(name);
 	if ((headlen < namelen) ||
@@ -545,6 +545,7 @@ int main(int ac, char **av)
 	int sha1_name = 0;
 	int shown_merge_point = 0;
 	int topo_order = 0;
+	int with_current_branch = 0;
 	int head_at = -1;
 
 	git_config(git_show_branch_config);
@@ -574,6 +575,8 @@ int main(int ac, char **av)
 			extra = -1;
 		else if (!strcmp(arg, "--no-name"))
 			no_name = 1;
+		else if (!strcmp(arg, "--current"))
+			with_current_branch = 1;
 		else if (!strcmp(arg, "--sha1-name"))
 			sha1_name = 1;
 		else if (!strncmp(arg, "--more=", 7))
@@ -605,6 +608,34 @@ int main(int ac, char **av)
 		ac--; av++;
 	}
 
+	head_path_p = resolve_ref(git_path("HEAD"), head_sha1, 1);
+	if (head_path_p) {
+		head_path_len = strlen(head_path_p);
+		memcpy(head_path, head_path_p, head_path_len + 1);
+	}
+	else {
+		head_path_len = 0;
+		head_path[0] = 0;
+	}
+
+	if (with_current_branch && head_path_p) {
+		int has_head = 0;
+		for (i = 0; !has_head && i < ref_name_cnt; i++) {
+			/* We are only interested in adding the branch
+			 * HEAD points at.
+			 */
+			if (rev_is_head(head_path,
+					head_path_len,
+					ref_name[i],
+					head_sha1, NULL))
+				has_head++;
+		}
+		if (!has_head) {
+			int pfxlen = strlen(git_path("refs/heads/"));
+			append_one_rev(head_path + pfxlen);
+		}
+	}
+
 	if (!ref_name_cnt) {
 		fprintf(stderr, "No revs to be shown.\n");
 		exit(0);
@@ -640,16 +671,6 @@ int main(int ac, char **av)
 	if (0 <= extra)
 		join_revs(&list, &seen, num_rev, extra);
 
-	head_path_p = resolve_ref(git_path("HEAD"), head_sha1, 1);
-	if (head_path_p) {
-		head_path_len = strlen(head_path_p);
-		memcpy(head_path, head_path_p, head_path_len + 1);
-	}
-	else {
-		head_path_len = 0;
-		head_path[0] = 0;
-	}
-
 	if (merge_base)
 		return show_merge_base(seen, num_rev);