pyreverse: Infinite loop with twisted

[pycqa]

pyreverse: Infinite loop with twisted

[pylint-bot]

Original comment by Sylvain Thénault (BitBucket: sthenault, GitHub: @sthenault?):

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I can reproduce using twisted 11.1 and 13.0 with python 2.7.3 / pylint 0.28 / astng 0.24.3, though pyreverse has to be launched on the whole twisted, not only on the tktree module (which seems analyzed fine during my tests)

[pylint-bot]

Original comment by Emile Anclin (BitBucket: anclin, GitHub: @Anclin?):

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It's an astroid bug that was not too easy to track since it appears only if the project is complicated enough to go repeatedly into the scoped_nodes.Class.instance_attr method, which is called only in the Instance class ; here is the diff :

#!diff


--- a/scoped_nodes.py   Wed May 21 18:29:15 2014 +0300
+++ b/scoped_nodes.py   Thu May 29 14:31:33 2014 +0200
@@ -941,7 +941,8 @@
           if no attribute with this name has been find in this class or
           its parent classes
         """
-        values = self.instance_attrs.get(name, [])
+        # ! don't modify the self.instance_attrs !
+        values = list(self.instance_attrs.get(name, []))
         # get all values from parents
         for class_node in self.instance_attr_ancestors(name, context):
             values += class_node.instance_attrs[name]

For smaller parts of twisted, the lists that are the values of instance_attrs get longer and longer, and for a bigger part it finally generates the infinite loop...

[pylint-bot]

Original comment by Claudiu Popa (BitBucket: PCManticore, GitHub: @PCManticore):

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This was fixed in astroid with https://bitbucket.org/logilab/astroid/commits/16d284f2bfd9b507c1606320be40b41d2d243f97.