[processing] fix handling of the multiple enum values

python/plugins/processing/gui/enummodelerwidget.py

@@ -83,13 +83,14 @@ def options(self):
 
         return items
 
-    def defaultOption(self):
+    def defaultOptions(self):
+        options = []
         model = self.lstItems.model()
         for i in range(model.rowCount()):
             item = model.item(i)
             if item.checkState() == Qt.Checked:
-                return i
-        return None
+                options.append(i)
+        return options if len(options) > 0 else None
 
     def allowMultiple(self):
         return self.chkAllowMultiple.isChecked()

python/plugins/processing/modeler/ModelerParameterDefinitionDialog.py

@@ -421,7 +421,7 @@ def accept(self):
             self.param = QgsProcessingParameterCrs(name, description, self.selector.crs().authid())
         elif (self.paramType == parameters.PARAMETER_ENUM or
                 isinstance(self.param, QgsProcessingParameterEnum)):
-            self.param = QgsProcessingParameterEnum(name, description, self.widget.options(), self.widget.allowMultiple(), self.widget.defaultOption())
+            self.param = QgsProcessingParameterEnum(name, description, self.widget.options(), self.widget.allowMultiple(), self.widget.defaultOptions())
         elif (self.paramType == parameters.PARAMETER_MATRIX or
                 isinstance(self.param, QgsProcessingParameterMatrix)):
             self.param = QgsProcessingParameterMatrix(name, description, hasFixedNumberRows=self.widget.fixedRows(), headers=self.widget.headers(), defaultValue=self.widget.value())