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, 24 insertions, 0 deletions

diff --git a/fsck.c b/fsck.c
index bed5e20..9c3a594 100644
--- a/fsck.c
+++ b/fsck.c
@@ -1310,3 +1310,27 @@ int fsck_finish(struct fsck_options *options)
 	oidset_clear(&gitmodules_done);
 	return ret;
 }
+
+int fsck_config_internal(const char *var, const char *value, void *cb,
+			 struct fsck_options *options)
+{
+	if (strcmp(var, "fsck.skiplist") == 0) {
+		const char *path;
+		struct strbuf sb = STRBUF_INIT;
+
+		if (git_config_pathname(&path, var, value))
+			return 1;
+		strbuf_addf(&sb, "skiplist=%s", path);
+		free((char *)path);
+		fsck_set_msg_types(options, sb.buf);
+		strbuf_release(&sb);
+		return 0;
+	}
+
+	if (skip_prefix(var, "fsck.", &var)) {
+		fsck_set_msg_type(options, var, value);
+		return 0;
+	}
+
+	return git_default_config(var, value, cb);
+}