Merge pull request #1048 from jyegerlehner/conv_layer-init-weight

Conv layer: fix crash by setting weight pointer

src/caffe/layers/conv_layer.cpp

@@ -203,6 +203,9 @@ void ConvolutionLayer<Dtype>::Backward_cpu(const vector<Blob<Dtype>*>& top,
         }
         // gradient w.r.t. bottom data, if necessary
         if (propagate_down[i]) {
+          if (weight == NULL) {
+            weight = this->blobs_[0]->cpu_data();
+          }
           for (int g = 0; g < group_; ++g) {
             caffe_cpu_gemm<Dtype>(CblasTrans, CblasNoTrans, K_, N_, M_,
                 (Dtype)1., weight + weight_offset * g,

src/caffe/layers/conv_layer.cu

@@ -96,6 +96,9 @@ void ConvolutionLayer<Dtype>::Backward_gpu(const vector<Blob<Dtype>*>& top,
         }
         // gradient w.r.t. bottom data, if necessary
         if (propagate_down[i]) {
+          if (weight == NULL) {
+            weight = this->blobs_[0]->gpu_data();
+          }
           for (int g = 0; g < group_; ++g) {
             caffe_gpu_gemm<Dtype>(CblasTrans, CblasNoTrans, K_, N_, M_,
                 (Dtype)1., weight + weight_offset * g,