Add custom subject prefix support to format-patch (take 3)

Add a new option to git-format-patch, entitled --subject-prefix that allows
control of the subject prefix '[PATCH]'. Using this option, the text 'PATCH' is
replaced with whatever input is provided to the option. This allows easily
generating patches like '[PATCH 2.6.21-rc3]' or properly numbered series like
'[-mm3 PATCH N/M]'. This patch provides the implementation and documentation.

Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 10 insertions, 4 deletions

diff --git a/log-tree.c b/log-tree.c
index 8797aa1..dad5513 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -165,14 +165,20 @@ void show_log(struct rev_info *opt, const char *sep)
 		if (opt->total > 0) {
 			static char buffer[64];
 			snprintf(buffer, sizeof(buffer),
-					"Subject: [PATCH %0*d/%d] ",
+					"Subject: [%s %0*d/%d] ",
+					opt->subject_prefix,
 					digits_in_number(opt->total),
 					opt->nr, opt->total);
 			subject = buffer;
-		} else if (opt->total == 0)
-			subject = "Subject: [PATCH] ";
-		else
+		} else if (opt->total == 0) {
+			static char buffer[256];
+			snprintf(buffer, sizeof(buffer),
+					"Subject: [%s] ",
+					opt->subject_prefix);
+			subject = buffer;
+		} else {
 			subject = "Subject: ";
+		}
 
 		printf("From %s Mon Sep 17 00:00:00 2001\n", sha1);
 		if (opt->message_id)