[Minor] Warn on fuzzy flag collisions across writable rules

Issue: #6003
PR: rspamd/docs.rspamd.com#99

diff --git a/src/plugins/fuzzy_check.c b/src/plugins/fuzzy_check.c
index c4efd31fea30a84a8f50057eb19ba088f274c371..50f6d49d48922404e0d749a343848f4dc5cf00d7 100644 (file)
--- a/src/plugins/fuzzy_check.c
+++ b/src/plugins/fuzzy_check.c
@@ -2944,6 +2944,44 @@ int fuzzy_check_module_config(struct rspamd_config *cfg, bool validate)
        msg_info_config("init internal fuzzy_check module, %d rules loaded",
                                        nrules);
 
+       /* Check for flag collisions across writable rules */
+       if (fuzzy_module_ctx->fuzzy_rules != NULL && fuzzy_module_ctx->fuzzy_rules->len > 1) {
+               GHashTable *writable_flag_rules = g_hash_table_new(g_direct_hash, g_direct_equal);
+               unsigned int ri;
+               struct fuzzy_rule *wrule;
+
+               PTR_ARRAY_FOREACH(fuzzy_module_ctx->fuzzy_rules, ri, wrule)
+               {
+                       if (wrule->mode == fuzzy_rule_read_only) {
+                               continue;
+                       }
+
+                       GHashTableIter flag_it;
+                       gpointer fk, fv;
+                       g_hash_table_iter_init(&flag_it, wrule->mappings);
+
+                       while (g_hash_table_iter_next(&flag_it, &fk, &fv)) {
+                               const char *existing_rule_name = g_hash_table_lookup(writable_flag_rules, fk);
+
+                               if (existing_rule_name != NULL) {
+                                       msg_warn_config(
+                                               "fuzzy flag %d is used by both writable rules '%s' and '%s'; "
+                                               "write operations will be sent to all matching rules — "
+                                               "use unique flags or set `read_only = true` on rules that should not receive writes",
+                                               GPOINTER_TO_INT(fk),
+                                               existing_rule_name,
+                                               wrule->name ? wrule->name : "(unnamed)");
+                               }
+                               else {
+                                       g_hash_table_insert(writable_flag_rules, fk,
+                                                                               (gpointer) (wrule->name ? wrule->name : "(unnamed)"));
+                               }
+                       }
+               }
+
+               g_hash_table_destroy(writable_flag_rules);
+       }
+
        /* Register global methods */
        lua_getglobal(L, "rspamd_plugins");