multi-detect: allow start up with 0 tenants

src/detect-engine.c

@@ -1996,6 +1996,7 @@ static DetectEngineThreadCtx *DetectEngineThreadCtxInitForMT(ThreadVars *tv)
     uint32_t map_cnt = 0;
     int max_tenant_id = 0;
     DetectEngineCtx *list = master->list;
+    DetectEngineThreadCtx **tenant_det_ctxs = NULL;
 
     while (list) {
         if (list->tenant_id > max_tenant_id)
@@ -2005,10 +2006,8 @@ static DetectEngineThreadCtx *DetectEngineThreadCtxInitForMT(ThreadVars *tv)
     }
 
     if (max_tenant_id == 0) {
-        SCLogInfo("no tenants left");
-        return NULL;
-    }
-
+        SCLogInfo("no tenants left, or none registered yet");
+    } else {
         max_tenant_id++;
 
         DetectEngineTenantMapping *map = master->tenant_mapping_list;
@@ -2037,7 +2036,7 @@ static DetectEngineThreadCtx *DetectEngineThreadCtxInitForMT(ThreadVars *tv)
 
         }
 
-    DetectEngineThreadCtx **tenant_det_ctxs = SCCalloc(max_tenant_id, sizeof(DetectEngineThreadCtx *));
+        tenant_det_ctxs = SCCalloc(max_tenant_id, sizeof(DetectEngineThreadCtx *));
         BUG_ON(tenant_det_ctxs == NULL);
 
         list = master->list;
@@ -2049,6 +2048,7 @@ static DetectEngineThreadCtx *DetectEngineThreadCtxInitForMT(ThreadVars *tv)
             }
             list = list->next;
         }
+    }
 
     DetectEngineThreadCtx *det_ctx = SCCalloc(1, sizeof(DetectEngineThreadCtx));
     if (det_ctx == NULL) {