Merge branch 'jn/update-contrib-example-merge'

* jn/update-contrib-example-merge: (24 commits)
  merge script: learn --[no-]rerere-autoupdate
  merge script: notice @{-1} shorthand
  merge script: handle --no-ff --no-commit correctly
  merge script: --ff-only to disallow true merge
  merge script: handle many-way octopus
  merge script: handle -m --log correctly
  merge script: forbid merge -s index
  merge script: allow custom strategies
  merge script: merge -X<option>
  merge script: improve log message subject
  merge script: refuse to merge during merge
  merge script: tweak unmerged files message to match builtin
  merge script: --squash, --ff from unborn branch are errors
  fmt-merge-msg -m to override merge title
  merge-base --independent to print reduced parent list in a merge
  merge-base --octopus to mimic show-branch --merge-base
  Documentation: add a SEE ALSO section for merge-base
  t6200 (fmt-merge-msg): style nitpicks
  t6010 (merge-base): modernize style
  t7600 (merge): test merge from branch yet to be born
  ...

1 files changed, 16 insertions, 2 deletions

diff --git a/builtin/fmt-merge-msg.c b/builtin/fmt-merge-msg.c
index a76cd4e9d1..e7e12eea25 100644
--- a/builtin/fmt-merge-msg.c
+++ b/builtin/fmt-merge-msg.c
@@ -7,7 +7,7 @@
 #include "string-list.h"
 
 static const char * const fmt_merge_msg_usage[] = {
-	"git fmt-merge-msg [--log|--no-log] [--file <file>]",
+	"git fmt-merge-msg [-m <message>] [--log|--no-log] [--file <file>]",
 	NULL
 };
 
@@ -319,11 +319,14 @@ int fmt_merge_msg_shortlog(struct strbuf *in, struct strbuf *out) {
 int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
 {
 	const char *inpath = NULL;
+	const char *message = NULL;
 	struct option options[] = {
 		OPT_BOOLEAN(0, "log",     &merge_summary, "populate log with the shortlog"),
 		{ OPTION_BOOLEAN, 0, "summary", &merge_summary, NULL,
 		  "alias for --log (deprecated)",
 		  PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
+		OPT_STRING('m', "message", &message, "text",
+			"use <text> as start of message"),
 		OPT_FILENAME('F', "file", &inpath, "file to read from"),
 		OPT_END()
 	};
@@ -337,6 +340,12 @@ int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
 			     0);
 	if (argc > 0)
 		usage_with_options(fmt_merge_msg_usage, options);
+	if (message && !merge_summary) {
+		char nl = '\n';
+		write_in_full(STDOUT_FILENO, message, strlen(message));
+		write_in_full(STDOUT_FILENO, &nl, 1);
+		return 0;
+	}
 
 	if (inpath && strcmp(inpath, "-")) {
 		in = fopen(inpath, "r");
@@ -346,7 +355,12 @@ int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
 
 	if (strbuf_read(&input, fileno(in), 0) < 0)
 		die_errno("could not read input file");
-	ret = fmt_merge_msg(merge_summary, &input, &output);
+	if (message) {
+		strbuf_addstr(&output, message);
+		ret = fmt_merge_msg_shortlog(&input, &output);
+	} else {
+		ret = fmt_merge_msg(merge_summary, &input, &output);
+	}
 	if (ret)
 		return ret;
 	write_in_full(STDOUT_FILENO, output.buf, output.len);