Bug #6255. Wrap gzip files with TextIOWrapper to allow them to be read as text.

svn: r21176

gramps/plugins/importer/importxml.py

@@ -371,7 +371,16 @@ class LineParser(object):
 
         try:
             if use_gzip:
-                ofile = gzip.open(filename, "rb")
+                import io
+                # Bug 6255. TextIOWrapper is required for python3 to present
+                #           file contents as text, otherwise they are read
+                #           as binary. However due to a missing method (read1)
+                #           in early python3 versions this try block will fail
+                #           It should work correctly from version 3.3
+                #           Gramps will still import XML files using python
+                #           versions < 3.3.0 but the file progress meter will
+                #           not work properly, going immediately to 100%.
+                ofile = io.TextIOWrapper(gzip.open(filename, "rb"))
             else:
                 ofile = open(filename, "r")
 
@@ -379,11 +388,12 @@ class LineParser(object):
                 self.count += 1
                 if PERSON_RE.match(line):
                     self.person_count += 1
-
-            ofile.close()
         except:
             self.count = 0
             self.person_count = 0
+        finally:
+            # Ensure the file handle is always closed
+            ofile.close()
 
     def get_count(self):
         return self.count