[PATCH v3 3/4] fetch-pack: split out fsck config parsing

[Justin Tobler <jltobler@gmail.com>]

When `fetch_pack_config()` is invoked, fetch-pack configuration is
parsed from the config. As part of this operation, fsck message severity
configuration is assigned to the `fsck_msg_types` global variable. This
is optionally used to configure the downstream git-index-pack(1) when
the `--strict` option is specified.

The same parsed fsck message severity configuration is also needed
outside of fetch-pack. Instead of exposing/relying on the existing
global state, split out the fsck config parsing logic into
`fetch_pack_fsck_config()` and expose it. In a subsequent commit, this
is used to provide fsck configuration when invoking `unbundle()`.

For `fetch_pack_fsck_config()` to discern between errors and unhandled
config variables, the return code when `git_config_path()` errors is
changed to a different value also indicating success. This frees up the
previous return code to now indicate the provided config variable
was unhandled. The behavior remains functionally the same.

Signed-off-by: Justin Tobler <jltobler@gmail.com>
---
 fetch-pack.c | 26 ++++++++++++++++++--------
 fetch-pack.h | 11 +++++++++++
 2 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/fetch-pack.c b/fetch-pack.c
index fe1fb3c1b7..c095f3a84b 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -1857,8 +1857,8 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
 	return ref;
 }
 
-static int fetch_pack_config_cb(const char *var, const char *value,
-				const struct config_context *ctx, void *cb)
+int fetch_pack_fsck_config(const char *var, const char *value,
+			   struct strbuf *msg_types)
 {
 	const char *msg_id;
 
@@ -1866,9 +1866,9 @@ static int fetch_pack_config_cb(const char *var, const char *value,
 		char *path ;
 
 		if (git_config_pathname(&path, var, value))
-			return 1;
-		strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
-			fsck_msg_types.len ? ',' : '=', path);
+			return 0;
+		strbuf_addf(msg_types, "%cskiplist=%s",
+			msg_types->len ? ',' : '=', path);
 		free(path);
 		return 0;
 	}
@@ -1877,14 +1877,24 @@ static int fetch_pack_config_cb(const char *var, const char *value,
 		if (!value)
 			return config_error_nonbool(var);
 		if (is_valid_msg_type(msg_id, value))
-			strbuf_addf(&fsck_msg_types, "%c%s=%s",
-				fsck_msg_types.len ? ',' : '=', msg_id, value);
+			strbuf_addf(msg_types, "%c%s=%s",
+				msg_types->len ? ',' : '=', msg_id, value);
 		else
 			warning("Skipping unknown msg id '%s'", msg_id);
 		return 0;
 	}
 
-	return git_default_config(var, value, ctx, cb);
+	return 1;
+}
+
+static int fetch_pack_config_cb(const char *var, const char *value,
+				const struct config_context *ctx, void *cb)
+{
+	int ret = fetch_pack_fsck_config(var, value, &fsck_msg_types);
+	if (ret > 0)
+		return git_default_config(var, value, ctx, cb);
+
+	return ret;
 }
 
 static void fetch_pack_config(void)
diff --git a/fetch-pack.h b/fetch-pack.h
index b5c579cdae..9d3470366f 100644
--- a/fetch-pack.h
+++ b/fetch-pack.h
@@ -106,4 +106,15 @@ int report_unmatched_refs(struct ref **sought, int nr_sought);
  */
 int fetch_pack_fsck_objects(void);
 
+/*
+ * Check if the provided config variable pertains to fetch fsck and if so append
+ * the configuration to the provided strbuf.
+ *
+ * When a fetch fsck config option is successfully processed the function
+ * returns 0. If the provided config option is unrelated to fetch fsck, 1 is
+ * returned. Errors return -1.
+ */
+int fetch_pack_fsck_config(const char *var, const char *value,
+			   struct strbuf *msg_types);
+
 #endif
-- 
2.47.0