add line number and file name info to config_set

Store file name and line number for each key-value pair in the cache
during parsing of the configuration files.

Signed-off-by: Tanay Abhra <tanayabh@gmail.com>
Reviewed-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

cache.h

@@ -1383,6 +1383,11 @@ extern int git_config_get_bool_or_int(const char *key, int *is_bool, int *dest);
 extern int git_config_get_maybe_bool(const char *key, int *dest);
 extern int git_config_get_pathname(const char *key, const char **dest);
 
+struct key_value_info {
+	const char *filename;
+	int linenr;
+};
+
 extern int committer_ident_sufficiently_given(void);
 extern int author_ident_sufficiently_given(void);
 

config.c

@@ -1262,6 +1262,9 @@ static struct config_set_element *configset_find_element(struct config_set *cs,
 static int configset_add_value(struct config_set *cs, const char *key, const char *value)
 {
 	struct config_set_element *e;
+	struct string_list_item *si;
+	struct key_value_info *kv_info = xmalloc(sizeof(*kv_info));
+
 	e = configset_find_element(cs, key);
 	/*
 	 * Since the keys are being fed by git_config*() callback mechanism, they
@@ -1274,7 +1277,16 @@ static int configset_add_value(struct config_set *cs, const char *key, const cha
 		string_list_init(&e->value_list, 1);
 		hashmap_add(&cs->config_hash, e);
 	}
-	string_list_append_nodup(&e->value_list, value ? xstrdup(value) : NULL);
+	si = string_list_append_nodup(&e->value_list, value ? xstrdup(value) : NULL);
+	if (cf) {
+		kv_info->filename = strintern(cf->name);
+		kv_info->linenr = cf->linenr;
+	} else {
+		/* for values read from `git_config_from_parameters()` */
+		kv_info->filename = NULL;
+		kv_info->linenr = -1;
+	}
+	si->util = kv_info;
 
 	return 0;
 }
@@ -1301,7 +1313,7 @@ void git_configset_clear(struct config_set *cs)
 	hashmap_iter_init(&cs->config_hash, &iter);
 	while ((entry = hashmap_iter_next(&iter))) {
 		free(entry->key);
-		string_list_clear(&entry->value_list, 0);
+		string_list_clear(&entry->value_list, 1);
 	}
 	hashmap_free(&cs->config_hash, 1);
 	cs->hash_initialized = 0;