Fix bug in 3.7 chained comparison semantic action

test/simple_source/bug33/01_triple_compare.py

@@ -14,3 +14,23 @@ def _is_valid_netmask(netmask):
 
 # See in 2.6.9 quopri.py ishex():
 assert not '0' <= __file__ <= '9' or 'a' <= __file__ <= 'f' or 'A' <= __file__ <= 'F'
+
+# From 3.7 bug-grammar.py
+
+# Bug in 3.7 was handling the last line where compare_chained -> compare_chained37 and
+# therefore compare_chained has one child, not two as it normally does.
+
+def test_comparison():
+    ### comparison: expr (comp_op expr)*
+    ### comp_op: '<'|'>'|'=='|'>='|'<='|'!='|'in'|'not' 'in'|'is'|'is' 'not'
+    if 1: pass
+    x = (1 == 1)
+    if 1 == 1: pass
+    if 1 != 1: pass
+    if 1 < 1: pass
+    if 1 > 1: pass
+    if 1 <= 1: pass
+    if 1 >= 1: pass
+    if 1 in (): pass
+    if 1 not in (): pass
+    if 1 < 1 > 1 == 1 >= 1 <= 1 != 1 in 1 not in 1 is 1 is not 1: pass

uncompyle6/semantics/customize37.py

@@ -276,6 +276,13 @@ def customize_for_version37(self, version):
 
     self.n_call = n_call
 
+    def n_compare_chained(node):
+        if node[0] == "compare_chained37":
+            self.default(node[0])
+        else:
+            self.default(node)
+    self.n_compare_chained = n_compare_chained
+
     def n_importlist37(node):
         if len(node) == 1:
             self.default(node)