fsck: make fsck_config() re-usable

Move the fsck_config() function from builtin/fsck.c to fsck.[ch]. This
allows for re-using it in other tools that expose fsck logic and want
to support its configuration variables.

A logical continuation of this change would be to use a common
function for all of {fetch,receive}.fsck.* and fsck.*. See
5d477a334a6 (fsck (receive-pack): allow demoting errors to warnings,
2015-06-22) and my own 1362df0d413 (fetch: implement fetch.fsck.*,
2018-07-27) for the relevant code.

However, those routines want to not parse the fsck.skipList into OIDs,
but rather pass them along with the --strict option to another
process. It would be possible to refactor that whole thing so we
support e.g. a "fetch." prefix, then just keep track of the skiplist
as a filename instead of parsing it, and learn to spew that all out
from our internal structures into something we can append to the
--strict option.

But instead I'm planning to re-use this in "mktag", which'll just
re-use these "fsck.*" variables as-is.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/fsck.h b/fsck.h
index 29ee4c45e8..423c467feb 100644
--- a/fsck.h
+++ b/fsck.h
@@ -103,4 +103,11 @@ void fsck_put_object_name(struct fsck_options *options,
 const char *fsck_describe_object(struct fsck_options *options,
 				 const struct object_id *oid);
 
+/*
+ * git_config() callback for use by fsck-y tools that want to support
+ * fsck.<msg> fsck.skipList etc.
+ */
+int fsck_config_internal(const char *var, const char *value, void *cb,
+			 struct fsck_options *options);
+
 #endif