+static void write_merge_msg(void)
+{
+ int fd = open(git_path("MERGE_MSG"), O_WRONLY | O_CREAT, 0666);
+ if (fd < 0)
+ die_errno("Could not open '%s' for writing",
+ git_path("MERGE_MSG"));
+ if (write_in_full(fd, merge_msg.buf, merge_msg.len) != merge_msg.len)
+ die_errno("Could not write to '%s'", git_path("MERGE_MSG"));
+ close(fd);
+}
+
+static void read_merge_msg(void)
+{
+ strbuf_reset(&merge_msg);
+ if (strbuf_read_file(&merge_msg, git_path("MERGE_MSG"), 0) < 0)
+ die_errno("Could not read from '%s'", git_path("MERGE_MSG"));
+}
+
+static void run_prepare_commit_msg(void)
+{
+ write_merge_msg();
+ run_hook(get_index_file(), "prepare-commit-msg",
+ git_path("MERGE_MSG"), "merge", NULL, NULL);
+ read_merge_msg();
+}
+