bpo-18374: fix wrong col_offset of some ast.BinOp instances (GH-14607)

Nested BinOp instances (e.g. a+b+c) had a wrong col_offset for the
second BinOp (e.g. 2 instead of 0 in the example). Fix it by using the
correct st node to copy the line and col_offset from in ast.c.

1 files changed, 30 insertions, 0 deletions

diff --git a/Lib/test/test_ast.py b/Lib/test/test_ast.py
index e251e25..1e07c57 100644
--- a/Lib/test/test_ast.py
+++ b/Lib/test/test_ast.py
@@ -576,6 +576,36 @@ class AST_Tests(unittest.TestCase):
         with support.swap_attr(unicodedata, 'normalize', bad_normalize):
             self.assertRaises(TypeError, ast.parse, '\u03D5')
 
+    def test_issue18374_binop_col_offset(self):
+        tree = ast.parse('4+5+6+7')
+        parent_binop = tree.body[0].value
+        child_binop = parent_binop.left
+        grandchild_binop = child_binop.left
+        self.assertEqual(parent_binop.col_offset, 0)
+        self.assertEqual(parent_binop.end_col_offset, 7)
+        self.assertEqual(child_binop.col_offset, 0)
+        self.assertEqual(child_binop.end_col_offset, 5)
+        self.assertEqual(grandchild_binop.col_offset, 0)
+        self.assertEqual(grandchild_binop.end_col_offset, 3)
+
+        tree = ast.parse('4+5-\\\n 6-7')
+        parent_binop = tree.body[0].value
+        child_binop = parent_binop.left
+        grandchild_binop = child_binop.left
+        self.assertEqual(parent_binop.col_offset, 0)
+        self.assertEqual(parent_binop.lineno, 1)
+        self.assertEqual(parent_binop.end_col_offset, 4)
+        self.assertEqual(parent_binop.end_lineno, 2)
+
+        self.assertEqual(child_binop.col_offset, 0)
+        self.assertEqual(parent_binop.lineno, 1)
+        self.assertEqual(child_binop.end_col_offset, 2)
+        self.assertEqual(parent_binop.end_lineno, 2)
+
+        self.assertEqual(grandchild_binop.col_offset, 0)
+        self.assertEqual(parent_binop.lineno, 1)
+        self.assertEqual(grandchild_binop.end_col_offset, 3)
+        self.assertEqual(parent_binop.end_lineno, 2)
 
 class ASTHelpers_Test(unittest.TestCase):
     maxDiff = None