builtin-commit.c: show on which branch a commit was added

This outputs the current branch on which a commit was created, just for
reference. For example:

Created commit 6d42875 on master: Fix submodule invalid command error

This also reminds the committer when he is on a detached HEAD:

Created commit 02a7172 on detached HEAD: Also do this for 'git commit --amend'

Signed-off-by: Pieter de Bie <pdebie@ai.rug.nl>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin-commit.c b/builtin-commit.c
index 8165bb3d31c6cdd92c83663c5dd081e564dcfc1e..f7b90604aa61c2cc77f154ccdfa4c0794c997c8f 100644 (file)
--- a/builtin-commit.c
+++ b/builtin-commit.c
@@ -878,10 +878,37 @@ int cmd_status(int argc, const char **argv, const char *prefix)
        return commitable ? 0 : 1;
 }
 
+static char *get_commit_format_string(void)
+{
+       unsigned char sha[20];
+       const char *head = resolve_ref("HEAD", sha, 0, NULL);
+       struct strbuf buf = STRBUF_INIT;
+
+       strbuf_addstr(&buf, "format:%h");
+
+       /* Are we on a detached HEAD? */
+       if (!strcmp("HEAD", head))
+               strbuf_addstr(&buf, " on detached HEAD");
+       else if (!prefixcmp(head, "refs/heads/")) {
+               const char *cp;
+               strbuf_addstr(&buf, " on ");
+               for (cp = head + 11; *cp; cp++) {
+                       if (*cp == '%')
+                               strbuf_addstr(&buf, "%x25");
+                       else
+                               strbuf_addch(&buf, *cp);
+               }
+       }
+       strbuf_addstr(&buf, ": %s");
+
+       return strbuf_detach(&buf, NULL);
+}
+
 static void print_summary(const char *prefix, const unsigned char *sha1)
 {
        struct rev_info rev;
        struct commit *commit;
+       char *format = get_commit_format_string();
 
        commit = lookup_commit(sha1);
        if (!commit)
@@ -899,7 +926,7 @@ static void print_summary(const char *prefix, const unsigned char *sha1)
 
        rev.verbose_header = 1;
        rev.show_root_diff = 1;
-       get_commit_format("format:%h: %s", &rev);
+       get_commit_format(format, &rev);
        rev.always_show_header = 0;
        rev.diffopt.detect_rename = 1;
        rev.diffopt.rename_limit = 100;
@@ -910,10 +937,11 @@ static void print_summary(const char *prefix, const unsigned char *sha1)
 
        if (!log_tree_commit(&rev, commit)) {
                struct strbuf buf = STRBUF_INIT;
-               format_commit_message(commit, "%h: %s", &buf, DATE_NORMAL);
+               format_commit_message(commit, format + 7, &buf, DATE_NORMAL);
                printf("%s\n", buf.buf);
                strbuf_release(&buf);
        }
+       free(format);
 }
 
 static int git_commit_config(const char *k, const char *v, void *cb)