fix for itnerpolate. test=develop

paddle/fluid/operators/interpolate_op.cc

@@ -45,9 +45,14 @@ class InterpolateOp : public framework::OperatorWithKernel {
       // round down
       out_h = static_cast<int>(dim_x[2] * scale);
       out_w = static_cast<int>(dim_x[3] * scale);
+      // protect when input shape is -1
+      out_h = out_h > 0 ? out_h : -1;
+      out_w = out_w > 0 ? out_w : -1;
     } else {
       out_h = ctx->Attrs().Get<int>("out_h");
       out_w = ctx->Attrs().Get<int>("out_w");
+      PADDLE_ENFORCE_GT(out_h, 0, "out_h should be greater than 0.");
+      PADDLE_ENFORCE_GT(out_w, 0, "out_w should be greater than 0.");
     }
 
     if (ctx->HasInput("OutSize") && ctx->IsRuntime()) {
@@ -59,12 +64,8 @@ class InterpolateOp : public framework::OperatorWithKernel {
       return;
     }
 
-    if (ctx->IsRuntime() || (out_h > 0 && out_w > 0)) {
     std::vector<int64_t> dim_out({dim_x[0], dim_x[1], out_h, out_w});
     ctx->SetOutputDim("Out", framework::make_ddim(dim_out));
-    } else {
-      ctx->SetOutputDim("Out", dim_x);
-    }
   }
 
  protected: