fsck: support demoting errors to warnings

We already have support in `git receive-pack` to deal with some legacy
repositories which have non-fatal issues.

Let's make `git fsck` itself useful with such repositories, too, by
allowing users to ignore known issues, or at least demote those issues
to mere warnings.

Example: `git -c fsck.missingEmail=ignore fsck` would hide
problems with missing emails in author, committer and tagger lines.

In the same spirit that `git receive-pack`'s usage of the fsck machinery
differs from `git fsck`'s – some of the non-fatal warnings in `git fsck`
are fatal with `git receive-pack` when receive.fsckObjects = true, for
example – we strictly separate the fsck.<msg-id> from the
receive.fsck.<msg-id> settings.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/builtin/fsck.c b/builtin/fsck.c
index cea623d3af..6dc2f94874 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -46,6 +46,16 @@ static int show_dangling = 1;
 #define DIRENT_SORT_HINT(de) ((de)->d_ino)
 #endif
 
+static int fsck_config(const char *var, const char *value, void *cb)
+{
+	if (skip_prefix(var, "fsck.", &var)) {
+		fsck_set_msg_type(&fsck_obj_options, var, value);
+		return 0;
+	}
+
+	return git_default_config(var, value, cb);
+}
+
 static void objreport(struct object *obj, const char *msg_type,
 			const char *err)
 {
@@ -640,6 +650,8 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
 		include_reflogs = 0;
 	}
 
+	git_config(fsck_config, NULL);
+
 	fsck_head_link();
 	fsck_object_dir(get_object_directory());