Merged few small fixes from 2.4 branch

modules/core/doc/xml_yaml_persistence.rst

@@ -201,6 +201,15 @@ Closes the file and releases all the memory buffers.
 
 .. ocv:function:: void FileStorage::release()
 
+Call this method after all I/O operations with the storage are finished.
+
+
+FileStorage::releaseAndGetString
+--------------------------------
+Closes the file and releases all the memory buffers.
+
+.. ocv:function:: string FileStorage::releaseAndGetString()
+
 Call this method after all I/O operations with the storage are finished. If the storage was opened for writing data and ``FileStorage::WRITE`` was specified
 
 

modules/core/src/persistence.cpp

@@ -5203,9 +5203,7 @@ string FileStorage::releaseAndGetString()
     if( fs.obj && fs.obj->outbuf )
         icvClose(fs.obj, &buf);
     
-    fs.release();
-    structs.clear();
-    state = UNDEFINED;
+    release();
 	return buf;
 }    
     

modules/highgui/src/cap_dshow.cpp

@@ -3278,7 +3278,7 @@ bool CvCaptureCAM_DShow::setProperty( int property_id, double value )
 
     case CV_CAP_PROP_FPS:
         int fps = cvRound(value);
-        if (fps != VI.getFPS(0))
+        if (fps != VI.getFPS(index))
         {
             VI.stopDevice(index);
             VI.setIdealFramerate(index,fps);