Fixed several issues found by static analysis

modules/objdetect/src/face_detect.cpp

@@ -142,6 +142,7 @@ private:
             {64.0f,  96.0f},
             {128.0f, 192.0f, 256.0f}
         };
+        CV_Assert(min_sizes.size() == feature_map_sizes.size()); // just to keep vectors in sync
         const std::vector<int> steps = { 8, 16, 32, 64 };
 
         // Generate priors

modules/objdetect/src/face_recognize.cpp

@@ -45,8 +45,8 @@ public:
     double match(InputArray _face_feature1, InputArray _face_feature2, int dis_type) const override
     {
         Mat face_feature1 = _face_feature1.getMat(), face_feature2 = _face_feature2.getMat();
-        face_feature1 /= norm(face_feature1);
-        face_feature2 /= norm(face_feature2);
+        normalize(face_feature1, face_feature1);
+        normalize(face_feature2, face_feature2);
 
         if(dis_type == DisType::FR_COSINE){
             return sum(face_feature1.mul(face_feature2))[0];

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;