Merge pull request #6038 from rldhont/server-qgis3-imagequality

[BUGFIX][Server] imageQuality has to be used for JPEG images not PNG

Author: rldhont

src/server/services/wms/qgswmsutils.cpp

@@ -153,7 +153,14 @@ namespace QgsWms
     if ( outputFormat != UNKN )
     {
       response.setHeader( "Content-Type", contentType );
-      result.save( response.io(), qPrintable( saveFormat ), imageQuality );
+      if ( saveFormat == "JPEG" )
+      {
+        result.save( response.io(), qPrintable( saveFormat ), imageQuality );
+      }
+      else
+      {
+        result.save( response.io(), qPrintable( saveFormat ) );
+      }
     }
     else
     {

tests/src/python/test_authmanager_password_ows.py

@@ -276,7 +276,7 @@ def testValidAuthFileDownload(self):
 
         # Check the we've got a likely PNG image
         self.assertTrue(self.completed_was_called)
-        self.assertTrue(os.path.getsize(destination) > 700000, "Image size: %s" % os.path.getsize(destination))  # > 1MB
+        self.assertTrue(os.path.getsize(destination) > 2000, "Image size: %s" % os.path.getsize(destination))  # > 1MB
         with open(destination, 'rb') as f:
             self.assertTrue(b'PNG' in f.read())  # is a PNG