help: add a build option for default hash

We'd like users to be able to determine the hash algorithm that is the
builtin default in their version of Git.  This is useful for
troubleshooting, especially when we decide to change the default.  Add
an entry for the default hash in the output of git version
--build-options so that users can easily access that information and
include it in bug reports.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/help.c b/help.c
index 21b778707a6a653b909d86e613b6d1109555ce1a..bd0be2ee574cc90e9f77ca5ab2b1bfcec6eb4efe 100644 (file)
--- a/help.c
+++ b/help.c
@@ -810,6 +810,7 @@ void get_version_info(struct strbuf *buf, int show_build_options)
                            SHA1_UNSAFE_BACKEND);
 #endif
                strbuf_addf(buf, "SHA-256: %s\n", SHA256_BACKEND);
+               strbuf_addf(buf, "default-hash: %s\n", hash_algos[GIT_HASH_DEFAULT].name);
        }
 }