[processing] fix temporary directories handling

Author: alexbruy

python/plugins/processing/gui/DestinationSelectionPanel.py

@@ -313,7 +313,7 @@ def getValue(self):
             return None
 
         if isinstance(self.parameter, QgsProcessingParameterFolderDestination):
-            return self.leText.text()
+            return key
 
         if isinstance(self.parameter, QgsProcessingParameterFileDestination):
             return key

src/core/processing/qgsprocessingparameters.cpp

@@ -3643,7 +3643,14 @@ bool QgsProcessingDestinationParameter::fromVariantMap( const QVariantMap &map )
 
 QString QgsProcessingDestinationParameter::generateTemporaryDestination() const
 {
-  return QgsProcessingUtils::generateTempFilename( name() + '.' + defaultFileExtension() );
+  if ( defaultFileExtension().isEmpty() )
+  {
+    return QgsProcessingUtils::generateTempFilename( name() );
+  }
+  else
+  {
+    return QgsProcessingUtils::generateTempFilename( name() + '.' + defaultFileExtension() );
+  }
 }
 
 bool QgsProcessingDestinationParameter::createByDefault() const