(3.4) Fixed several issues found by static analysis

original commit: a079c2e

Author: mshabunin

modules/dnn/src/onnx/onnx_importer.cpp

@@ -1821,7 +1821,9 @@ void ONNXImporter::parseUnsqueeze(LayerParams& layerParams, const opencv_onnx::N
         }
         CV_Assert(axes.getIntValue(axes.size()-1) <= dims.size());
         for (int j = 0; j < axes.size(); j++) {
-            dims.insert(dims.begin() + axes.getIntValue(j), 1);
+            const int idx = axes.getIntValue(j);
+            CV_Assert(idx <= dims.size());
+            dims.insert(dims.begin() + idx, 1);
         }
 
         Mat out = input.reshape(0, dims);

modules/objdetect/src/qrcode_encoder.cpp

@@ -881,6 +881,8 @@ void QRCodeEncoderImpl::findAutoMaskType()
                 total_modules += 1;
             }
         }
+        if (total_modules == 0)
+            continue; // TODO: refactor, extract functions to reduce complexity
         int modules_percent = dark_modules * 100 / total_modules;
         int lower_bound = 45;
         int upper_bound = 55;