config: Improve "Unknown section name" error with more details

diff --git a/src/config/config-parser.c b/src/config/config-parser.c
index 78070b15d9099f6e6096d61fc24462a455055f9d..b97db6298c4be055537ee81154d3be96e7c77809 100644 (file)
--- a/src/config/config-parser.c
+++ b/src/config/config-parser.c
@@ -2762,18 +2762,23 @@ void config_parser_apply_line(struct config_parser_context *ctx,
                const struct config_filter *cur_filter =
                        &ctx->cur_section->filter_parser->filter;
                const char *key = line->key;
+               string_t *attempts = NULL;
                if (cur_filter->filter_name != NULL) {
                        const char *filter_key =
                                t_str_replace(cur_filter->filter_name, '/', '_');
                        const char *key2 = t_strdup_printf("%s_%s",
                                                           filter_key, key);
+                       attempts = t_str_new(64);
                        if (config_key_can_autoprefix(ctx, key2))
                                key = key2;
                        else {
+                               str_printfa(attempts, " (%s", key2);
                                filter_key = t_strcut(cur_filter->filter_name, '/');
                                key2 = t_strdup_printf("%s_%s", filter_key, key);
                                if (config_key_can_autoprefix(ctx, key2))
                                        key = key2;
+                               else
+                                       str_printfa(attempts, ", %s", key2);
                        }
                } else {
                        i_assert(!cur_filter->filter_name_array);
@@ -2791,8 +2796,11 @@ void config_parser_apply_line(struct config_parser_context *ctx,
                if (hash_table_lookup(ctx->all_keys, key) == NULL) {
                        if (ctx->ignore_unknown)
                                break;
+                       if (attempts != NULL)
+                               str_append(attempts, " not found either.)");
                        ctx->error = p_strdup_printf(ctx->pool,
-                               "Unknown section name: %s", key);
+                               "Unknown section name: %s%s", key,
+                               attempts == NULL ? "" : str_c(attempts));
                        break;
                }