X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=builtin%2Fmerge.c;h=5126443fdfe1dc5113943dd3099ab8d87d84887e;hb=d387868a7d29621e85e8c5c061d1f50586db74e5;hp=3a451727d0e637ae197c9a1193435e57e84e6c58;hpb=96e33609974a79e6826dc62d008a8bc9c0923612;p=git.git

diff --git a/builtin/merge.c b/builtin/merge.c
index 3a451727d..5126443fd 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -48,7 +48,7 @@ static const char * const builtin_merge_usage[] = {
 
 static int show_diffstat = 1, shortlog_len = -1, squash;
 static int option_commit = 1, allow_fast_forward = 1;
-static int fast_forward_only, option_edit;
+static int fast_forward_only, option_edit = -1;
 static int allow_trivial = 1, have_message;
 static int overwrite_ignore = 1;
 static struct strbuf merge_msg = STRBUF_INIT;
@@ -193,7 +193,7 @@ static struct option builtin_merge_options[] = {
 		"create a single commit instead of doing a merge"),
 	OPT_BOOLEAN(0, "commit", &option_commit,
 		"perform a commit if the merge succeeds (default)"),
-	OPT_BOOLEAN('e', "edit", &option_edit,
+	OPT_BOOL('e', "edit", &option_edit,
 		"edit message before committing"),
 	OPT_BOOLEAN(0, "ff", &allow_fast_forward,
 		"allow fast-forward (default)"),
@@ -885,11 +885,21 @@ static void abort_commit(const char *err_msg)
 	exit(1);
 }
 
+static const char merge_editor_comment[] =
+N_("Please enter a commit message to explain why this merge is necessary,\n"
+   "especially if it merges an updated upstream into a topic branch.\n"
+   "\n"
+   "Lines starting with '#' will be ignored, and an empty message aborts\n"
+   "the commit.\n");
+
 static void prepare_to_commit(void)
 {
 	struct strbuf msg = STRBUF_INIT;
+	const char *comment = _(merge_editor_comment);
 	strbuf_addbuf(&msg, &merge_msg);
 	strbuf_addch(&msg, '\n');
+	if (0 < option_edit)
+		strbuf_add_lines(&msg, "# ", comment, strlen(comment));
 	write_merge_msg(&msg);
 	run_hook(get_index_file(), "prepare-commit-msg",
 		 git_path("MERGE_MSG"), "merge", NULL, NULL);
@@ -1099,6 +1109,33 @@ static void write_merge_state(void)
 	close(fd);
 }
 
+static int default_edit_option(void)
+{
+	static const char name[] = "GIT_MERGE_AUTOEDIT";
+	const char *e = getenv(name);
+	struct stat st_stdin, st_stdout;
+
+	if (have_message)
+		/* an explicit -m msg without --[no-]edit */
+		return 0;
+
+	if (e) {
+		int v = git_config_maybe_bool(name, e);
+		if (v < 0)
+			die("Bad value '%s' in environment '%s'", e, name);
+		return v;
+	}
+
+	/* Use editor if stdin and stdout are the same and is a tty */
+	return (!fstat(0, &st_stdin) &&
+		!fstat(1, &st_stdout) &&
+		isatty(0) && isatty(1) &&
+		st_stdin.st_dev == st_stdout.st_dev &&
+		st_stdin.st_ino == st_stdout.st_ino &&
+		st_stdin.st_mode == st_stdout.st_mode);
+}
+
+
 int cmd_merge(int argc, const char **argv, const char *prefix)
 {
 	unsigned char result_tree[20];
@@ -1283,14 +1320,19 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 			    sha1_to_hex(commit->object.sha1));
 		setenv(buf.buf, argv[i], 1);
 		strbuf_reset(&buf);
-		if (merge_remote_util(commit) &&
+		if (!fast_forward_only &&
+		    merge_remote_util(commit) &&
 		    merge_remote_util(commit)->obj &&
 		    merge_remote_util(commit)->obj->type == OBJ_TAG) {
-			option_edit = 1;
+			if (option_edit < 0)
+				option_edit = default_edit_option();
 			allow_fast_forward = 0;
 		}
 	}
 
+	if (option_edit < 0)
+		option_edit = 0;
+
 	if (!use_strategies) {
 		if (!remoteheads->next)
 			add_strategies(pull_twohead, DEFAULT_TWOHEAD);