Add the --numbered-files option to git-format-patch.

With this option, git-format-patch will generate simple
numbered files as output instead of the default using
with the first commit line appended.

This simplifies the ability to generate an MH-style
drafts folder with each message to be sent.

Signed-off-by: Jon Loeliger <jdl@freescale.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-format-patch.txt

@@ -11,7 +11,8 @@ SYNOPSIS
 [verse]
 'git-format-patch' [-n | -k] [-o <dir> | --stdout] [--thread]
                    [--attach[=<boundary>] | --inline[=<boundary>]]
-                   [-s | --signoff] [<common diff options>] [--start-number <n>]
+                   [-s | --signoff] [<common diff options>]
+                   [--start-number <n>] [--numbered-files]
                    [--in-reply-to=Message-Id] [--suffix=.<sfx>]
                    [--ignore-if-in-upstream]
                    [--subject-prefix=Subject-Prefix]
@@ -30,9 +31,11 @@ gitlink:git-rev-parse[1].
 The output of this command is convenient for e-mail submission or
 for use with gitlink:git-am[1].
 
-Each output file is numbered sequentially from 1, and uses the
+By default, each output file is numbered sequentially from 1, and uses the
 first line of the commit message (massaged for pathname safety) as
-the filename. The names of the output files are printed to standard
+the filename. With the --numbered-files option, the output file names
+will only be numbers, without the first line of the commit appended.
+The names of the output files are printed to standard
 output, unless the --stdout option is specified.
 
 If -o is specified, output files are created in <dir>.  Otherwise
@@ -60,6 +63,11 @@ include::diff-options.txt[]
 --start-number <n>::
 	Start numbering the patches at <n> instead of 1.
 
+--numbered-files::
+	Output file names will be a simple number sequence
+	without the default first line of the commit appended.
+	Mutually exclusive with the --stdout option.
+
 -k|--keep-subject::
 	Do not strip/add '[PATCH]' from the first line of the
 	commit log message.

builtin-log.c

@@ -298,7 +298,8 @@ static int git_format_config(const char *var, const char *value)
 static FILE *realstdout = NULL;
 static const char *output_directory = NULL;
 
-static int reopen_stdout(struct commit *commit, int nr, int keep_subject)
+static int reopen_stdout(struct commit *commit, int nr, int keep_subject,
+			 int numbered_files)
 {
 	char filename[PATH_MAX];
 	char *sol;
@@ -315,6 +316,11 @@ static int reopen_stdout(struct commit *commit, int nr, int keep_subject)
 			filename[len++] = '/';
 	}
 
+	if (numbered_files) {
+		sprintf(filename + len, "%d", nr);
+		len = strlen(filename);
+
+	} else {
 		sprintf(filename + len, "%04d", nr);
 		len = strlen(filename);
 
@@ -350,18 +356,21 @@ static int reopen_stdout(struct commit *commit, int nr, int keep_subject)
 				} else
 					space = 1;
 			}
-		while (filename[len - 1] == '.' || filename[len - 1] == '-')
+			while (filename[len - 1] == '.'
+			       || filename[len - 1] == '-')
 				len--;
 			filename[len] = 0;
 		}
 		if (len + suffix_len >= sizeof(filename))
 			return error("Patch pathname too long");
 		strcpy(filename + len, fmt_patch_suffix);
+	}
+
 	fprintf(realstdout, "%s\n", filename);
 	if (freopen(filename, "w", stdout) == NULL)
 		return error("Cannot open patch file %s",filename);
-	return 0;
 
+	return 0;
 }
 
 static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids, const char *prefix)
@@ -431,6 +440,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	int numbered = 0;
 	int start_number = -1;
 	int keep_subject = 0;
+	int numbered_files = 0;		/* _just_ numbers */
 	int subject_prefix = 0;
 	int ignore_if_in_upstream = 0;
 	int thread = 0;
@@ -465,6 +475,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			numbered = 1;
 		else if (!prefixcmp(argv[i], "--start-number="))
 			start_number = strtol(argv[i] + 15, NULL, 10);
+		else if (!strcmp(argv[i], "--numbered-files"))
+			numbered_files = 1;
 		else if (!strcmp(argv[i], "--start-number")) {
 			i++;
 			if (i == argc)
@@ -540,6 +552,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		die ("-n and -k are mutually exclusive.");
 	if (keep_subject && subject_prefix)
 		die ("--subject-prefix and -k are mutually exclusive.");
+	if (numbered_files && use_stdout)
+		die ("--numbered-files and --stdout are mutually exclusive.");
 
 	argc = setup_revisions(argc, argv, &rev, "HEAD");
 	if (argc > 1)
@@ -614,7 +628,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			rev.message_id = message_id;
 		}
 		if (!use_stdout)
-			if (reopen_stdout(commit, rev.nr, keep_subject))
+			if (reopen_stdout(commit, rev.nr, keep_subject,
+					  numbered_files))
 				die("Failed to create output files");
 		shown = log_tree_commit(&rev, commit);
 		free(commit->buffer);