Fix issue PythonCharmers#45: exception when replacing urllib usage

edschofield · edschofield · commit 0a8cfd7ab997 · 2014-04-12T07:17:54.000+10:00
* The transform_member() function in lib2to3/fixes/fix_urllib.py breaks the
* node object that is passed to it. This patch finds the root node
* before calling that function so we can add the appropriate standard_library
* import.
diff --git a/libfuturize/fixer_util.py b/libfuturize/fixer_util.py
@@ -292,14 +292,14 @@ def touch_import_top(package, name_to_import, node):
     """Works like `does_tree_import` but adds an import statement at the
     top if it was not imported (but below any __future__ imports).
 
-    Calling this multiple times adds them in reverse order.
+    Based on lib2to3.fixer_util.touch_import()
+
+    Calling this multiple times adds the imports in reverse order.
         
     Also adds "standard_library.install_hooks()" after "from future import
-    standard_library". This should probably be factored into another function
-    somehow.
-
-    Based on lib2to3.fixer_util.touch_import()
+    standard_library". This should probably be factored into another function.
     """
+
     root = find_root(node)
 
     if does_tree_import(package, name_to_import, root):
diff --git a/libfuturize/fixes/fix_future_standard_library_urllib.py b/libfuturize/fixes/fix_future_standard_library_urllib.py
@@ -12,16 +12,19 @@
 """
 
 from lib2to3.fixes.fix_urllib import FixUrllib
-from libfuturize.fixer_util import touch_import_top
+from libfuturize.fixer_util import touch_import_top, find_root
 
 
 class FixFutureStandardLibraryUrllib(FixUrllib):     # not a subclass of FixImports
     run_order = 8
 
     def transform(self, node, results):
+        # transform_member() in lib2to3/fixes/fix_urllib.py breaks node so find_root(node)
+        # no longer works after the super() call below. So we find the root first:
+        root = find_root(node)
         result = super(FixFutureStandardLibraryUrllib, self).transform(node, results)
         # TODO: add a blank line between any __future__ imports and this?
-        touch_import_top(u'future', u'standard_library', node)
+        touch_import_top(u'future', u'standard_library', root)
         return result
 
 
