git-format-patch --start-number <n>

Since the "a..b c..d" syntax is interpreted as "b ^a d ^c" as other
range-ish commands, if you want to format a..b and then c..d and end
up with files consecutively numbered, the second run needs to be able
to tell the command what number to start from.

This does not imply --numbered (which gives [PATCH n/m] to the subject).

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

builtin-log.c

@@ -148,6 +148,7 @@ int cmd_format_patch(int argc, const char **argv, char **envp)
 	int nr = 0, total, i, j;
 	int use_stdout = 0;
 	int numbered = 0;
+	int start_number = -1;
 	int keep_subject = 0;
 
 	init_revisions(&rev);
@@ -171,7 +172,14 @@ int cmd_format_patch(int argc, const char **argv, char **envp)
 		else if (!strcmp(argv[i], "-n") ||
 				!strcmp(argv[i], "--numbered"))
 			numbered = 1;
-		else if (!strcmp(argv[i], "-k") ||
+		else if (!strncmp(argv[i], "--start-number=", 15))
+			start_number = strtol(argv[i] + 15, NULL, 10);
+		else if (!strcmp(argv[i], "--start-number")) {
+			i++;
+			if (i == argc)
+				die("Need a number for --start-number");
+			start_number = strtol(argv[i], NULL, 10);
+		} else if (!strcmp(argv[i], "-k") ||
 				!strcmp(argv[i], "--keep-subject")) {
 			keep_subject = 1;
 			rev.total = -1;
@@ -193,6 +201,8 @@ int cmd_format_patch(int argc, const char **argv, char **envp)
 	}
 	argc = j;
 
+	if (numbered && start_number < 0)
+		start_number = 1;
 	if (numbered && keep_subject < 0)
 		die ("-n and -k are mutually exclusive.");
 
@@ -219,11 +229,11 @@ int cmd_format_patch(int argc, const char **argv, char **envp)
 	}
 	total = nr;
 	if (numbered)
-		rev.total = total;
+		rev.total = total + start_number - 1;
 	while (0 <= --nr) {
 		int shown;
 		commit = list[nr];
-		rev.nr = total - nr;
+		rev.nr = rev.total - nr;
 		if (!use_stdout)
 			reopen_stdout(commit, rev.nr, keep_subject);
 		shown = log_tree_commit(&rev, commit);