Do not generate full commit log message if it is not going to be used

diff --git a/builtin-commit.c b/builtin-commit.c
index a35881e20b2ba8a71a047a2a264e496ceb56ff05..1a9a2568815c3eaee5adbe2392a1969aa647f9f5 100644 (file)
--- a/builtin-commit.c
+++ b/builtin-commit.c
@@ -367,6 +367,28 @@ static int prepare_log_message(const char *index_file, const char *prefix)
 
        strbuf_release(&sb);
 
+       if (no_edit) {
+               struct rev_info rev;
+               unsigned char sha1[40];
+
+               fclose(fp);
+
+               if (!active_nr && read_cache() < 0)
+                       die("Cannot read index");
+
+               if (get_sha1("HEAD", sha1) != 0)
+                       return !!active_nr;
+
+               init_revisions(&rev, "");
+               rev.abbrev = 0;
+               setup_revisions(0, NULL, &rev, "HEAD");
+               DIFF_OPT_SET(&rev.diffopt, QUIET);
+               DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
+               run_diff_index(&rev, 1 /* cached */);
+
+               return !!DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES);
+       }
+
        if (in_merge && !no_edit)
                fprintf(fp,
                        "#\n"