make multiline field tolerate scalar values; header row factory is now special class assigned in base class

expert/field.py

@@ -179,7 +179,10 @@ class MultiLineField(Field):
         return self.getRawValue(row)
 
     def getDisplayValues(self, row):
-        return self.getValue(row)
+        value = self.getValue(row)
+        if not isinstance(value, (list, tuple)):
+            value = [value]
+        return value
 
 
 # sub-report stuff

expert/report.py

@@ -77,7 +77,7 @@ class ReportInstance(BaseReport):
     adapts(IReport)
 
     rowFactory = Row
-    headerRowFactory = Row
+    #headerRowFactory = Row
 
     view = None     # set upon creation
 
@@ -103,7 +103,6 @@ class ReportInstance(BaseReport):
         result = list(self.selectObjects(parts))  # may modify parts
         qc = CompoundQueryCriteria(parts)
         return ResultSet(self, result, rowFactory=self.rowFactory,
-                         headerRowFactory=self.headerRowFactory,
                          sortCriteria=self.getSortCriteria(), queryCriteria=qc)
     def selectObjects(self, parts):
         # to be implemented by subclass