!6521 [Auto parallel] Checking the return value of find() in rec-searching

Merge pull request !6521 from Xiaoda/24-fix-a-return-value-checking-bug-in-rec-searching

mindspore/ccsrc/frontend/parallel/auto_parallel/rec_core/rec_generate_strategy.cc

@@ -487,6 +487,9 @@ Dimensions PrepareIncomingOperatorInputStrategy(const std::vector<std::shared_pt
   }
   if (ops[incoming_op_index]->type() == GATHERV2) {
     auto pos = ops[incoming_op_index]->name().find("Info");
+    if (pos == std::string::npos) {
+      return s;
+    }
     auto name = ops[incoming_op_index]->name().substr(0, pos);
     if (name == "GatherV2") {
       return s;