# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1481126526 -3600
# Node ID 93eb0a0ab92fa64d00e751bd8e5f8db9ee753610
# Parent  5c51c957f560a0de682f41928a833ae5996cc6c4
Detect and avoid encoded name conflicts.

diff -r 5c51c957f560 -r 93eb0a0ab92f encoders.py
--- a/encoders.py	Wed Dec 07 17:00:12 2016 +0100
+++ b/encoders.py	Wed Dec 07 17:02:06 2016 +0100
@@ -344,6 +344,10 @@
 
     return "__constvalue%d" % n
 
+# Track all encoded paths, detecting and avoiding conflicts.
+
+all_encoded_paths = {}
+
 def encode_path(path):
 
     "Encode 'path' as an output program object, translating special symbols."
@@ -351,7 +355,26 @@
     if path in reserved_words:
         return "__%s" % path
     else:
-        return path.replace("#", "__").replace("$", "__").replace(".", "_")
+        part_encoded = path.replace("#", "__").replace("$", "__")
+        encoded = part_encoded.replace(".", "_")
+
+        # Test for a conflict with the encoding of a different path, re-encoding
+        # if necessary.
+
+        previous = all_encoded_paths.get(encoded)
+        replacement = "_"
+
+        while previous:
+            if path == previous:
+                return encoded
+            replacement += "_"
+            encoded = part_encoded.replace(".", replacement)
+            previous = all_encoded_paths.get(encoded)
+
+        # Store any new or re-encoded path.
+
+        all_encoded_paths[encoded] = path
+        return encoded
 
 def encode_predefined_reference(path):
 
diff -r 5c51c957f560 -r 93eb0a0ab92f tests/name_encoding.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/name_encoding.py	Wed Dec 07 17:02:06 2016 +0100
@@ -0,0 +1,14 @@
+class C:
+    def f(self):
+        return 1
+
+def C_f():
+    return 2
+
+def C__f():
+    return 3
+
+c = C()
+print c.f()
+print C_f()
+print C__f()