[processing][gdal] Skip expensive parameter validation when just showing command in dialog

nyalldawson · nyalldawson · commit 6604def2e710 · 2018-03-22T11:27:31.000+11:00
(cherry-picked from 044470d)
diff --git a/python/plugins/processing/algs/gdal/GdalAlgorithmDialog.py b/python/plugins/processing/algs/gdal/GdalAlgorithmDialog.py
@@ -113,7 +113,7 @@ def parametersHaveChanged(self):
                     parameters[output.name()] = self.tr("[temporary file]")
             for p in self.alg.parameterDefinitions():
                 if (not p.name() in parameters and not p.flags() & QgsProcessingParameterDefinition.FlagOptional) \
-                        or (not p.checkValueIsAcceptable(parameters[p.name()], context)):
+                        or (not p.checkValueIsAcceptable(parameters[p.name()])):
                     # not ready yet
                     self.text.setPlainText('')
                     return
diff --git a/python/plugins/processing/algs/gdal/buildvrt.py b/python/plugins/processing/algs/gdal/buildvrt.py
@@ -115,10 +115,11 @@ def getConsoleCommands(self, parameters, context, feedback, executing=True):
         # length of the command will be longer then allowed in command prompt
         listFile = os.path.join(QgsProcessingUtils.tempFolder(), 'buildvrtInputFiles.txt')
         with open(listFile, 'w') as f:
-            layers = []
-            for l in self.parameterAsLayerList(parameters, self.INPUT, context):
-                layers.append(l.source())
-            f.write('\n'.join(layers))
+            if executing:
+                layers = []
+                for l in self.parameterAsLayerList(parameters, self.INPUT, context):
+                    layers.append(l.source())
+                f.write('\n'.join(layers))
         arguments.append('-input_file_list')
         arguments.append(listFile)
 
