cherry-pick: add --allow-empty-message option

diff --git a/builtin/update-index.c b/builtin/update-index.c
index a6a23fa1f3c7782566d7fcfe470dd424b876e4a5..5f038d64da38820ebaa73ff73d1082e17c3c80d2 100644 (file)
--- a/builtin/update-index.c
+++ b/builtin/update-index.c
@@ -708,6 +708,7 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
        int newfd, entries, has_errors = 0, line_termination = '\n';
        int read_from_stdin = 0;
        int prefix_length = prefix ? strlen(prefix) : 0;
+       int preferred_index_format = 0;
        char set_executable_bit = 0;
        struct refresh_params refresh_args = {0, &has_errors};
        int lock_error = 0;
@@ -791,6 +792,8 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
                        "(for porcelains) forget saved unresolved conflicts",
                        PARSE_OPT_NOARG | PARSE_OPT_NONEG,
                        resolve_undo_clear_callback},
+               OPT_INTEGER(0, "index-version", &preferred_index_format,
+                           "write index in this format"),
                OPT_END()
        };
 
@@ -851,6 +854,17 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
                }
        }
        argc = parse_options_end(&ctx);
+       if (preferred_index_format) {
+               if (preferred_index_format < INDEX_FORMAT_LB ||
+                   INDEX_FORMAT_UB < preferred_index_format)
+                       die("index-version %d not in range: %d..%d",
+                           preferred_index_format,
+                           INDEX_FORMAT_LB, INDEX_FORMAT_UB);
+
+               if (the_index.version != preferred_index_format)
+                       active_cache_changed = 1;
+               the_index.version = preferred_index_format;
+       }
 
        if (read_from_stdin) {
                struct strbuf buf = STRBUF_INIT, nbuf = STRBUF_INIT;