Merge pull request #8023 from sovrasov:fs_add_full_yml_type_heading

modules/core/src/persistence.cpp

@@ -1475,6 +1475,26 @@ icvYMLParseValue( CvFileStorage* fs, char* ptr, CvFileNode* node,
             ptr++;
             value_type |= CV_NODE_USER;
         }
+        if ( d == '<') //support of full type heading from YAML 1.2
+        {
+            const char* yamlTypeHeading = "<tag:yaml.org,2002:";
+            const size_t headingLenght = strlen(yamlTypeHeading);
+
+            char* typeEndPtr = ++ptr;
+
+            do d = *++typeEndPtr;
+            while( cv_isprint(d) && d != ' ' && d != '>' );
+
+            if ( d == '>' && (size_t)(typeEndPtr - ptr) > headingLenght )
+            {
+                if ( memcmp(ptr, yamlTypeHeading, headingLenght) == 0 )
+                {
+                    value_type |= CV_NODE_USER;
+                    *typeEndPtr = ' ';
+                    ptr += headingLenght - 1;
+                }
+            }
+        }
 
         endptr = ptr++;
         do d = *++endptr;

modules/core/test/test_io.cpp

@@ -996,3 +996,20 @@ TEST(Core_InputOutput, filestorage_vec_vec_io)
         remove((fileName + formats[i]).c_str());
     }
 }
+
+TEST(Core_InputOutput, filestorage_yaml_advanvced_type_heading)
+{
+    String content = "%YAML:1.0\n cameraMatrix: !<tag:yaml.org,2002:opencv-matrix>\n"
+            "   rows: 1\n"
+            "   cols: 1\n"
+            "   dt: d\n"
+            "   data: [ 1. ]";
+
+    cv::FileStorage fs(content, cv::FileStorage::READ | cv::FileStorage::MEMORY);
+
+    cv::Mat inputMatrix;
+    cv::Mat actualMatrix = cv::Mat::eye(1, 1, CV_64F);
+    fs["cameraMatrix"] >> inputMatrix;
+
+    ASSERT_EQ(cv::norm(inputMatrix, actualMatrix, NORM_INF), 0.);
+}