gh-106922: Support multi-line error locations in traceback (attempt 2)

Doc/library/traceback.rst

@@ -523,36 +523,41 @@ The output for the example would look similar to this:
    *** print_tb:
      File "<doctest...>", line 10, in <module>
        lumberjack()
+       ~~~~~~~~~~^^
    *** print_exception:
    Traceback (most recent call last):
      File "<doctest...>", line 10, in <module>
        lumberjack()
+       ~~~~~~~~~~^^
      File "<doctest...>", line 4, in lumberjack
        bright_side_of_life()
+       ~~~~~~~~~~~~~~~~~~~^^
    IndexError: tuple index out of range
    *** print_exc:
    Traceback (most recent call last):
      File "<doctest...>", line 10, in <module>
        lumberjack()
+       ~~~~~~~~~~^^
      File "<doctest...>", line 4, in lumberjack
        bright_side_of_life()
+       ~~~~~~~~~~~~~~~~~~~^^
    IndexError: tuple index out of range
    *** format_exc, first and last line:
    Traceback (most recent call last):
    IndexError: tuple index out of range
    *** format_exception:
    ['Traceback (most recent call last):\n',
-    '  File "<doctest default[0]>", line 10, in <module>\n    lumberjack()\n',
-    '  File "<doctest default[0]>", line 4, in lumberjack\n    bright_side_of_life()\n',
+    '  File "<doctest default[0]>", line 10, in <module>\n    lumberjack()\n    ~~~~~~~~~~^^\n',
+    '  File "<doctest default[0]>", line 4, in lumberjack\n    bright_side_of_life()\n    ~~~~~~~~~~~~~~~~~~~^^\n',
     '  File "<doctest default[0]>", line 7, in bright_side_of_life\n    return tuple()[0]\n           ~~~~~~~^^^\n',
     'IndexError: tuple index out of range\n']
    *** extract_tb:
    [<FrameSummary file <doctest...>, line 10 in <module>>,
     <FrameSummary file <doctest...>, line 4 in lumberjack>,
     <FrameSummary file <doctest...>, line 7 in bright_side_of_life>]
    *** format_tb:
-   ['  File "<doctest default[0]>", line 10, in <module>\n    lumberjack()\n',
-    '  File "<doctest default[0]>", line 4, in lumberjack\n    bright_side_of_life()\n',
+   ['  File "<doctest default[0]>", line 10, in <module>\n    lumberjack()\n    ~~~~~~~~~~^^\n',
+    '  File "<doctest default[0]>", line 4, in lumberjack\n    bright_side_of_life()\n    ~~~~~~~~~~~~~~~~~~~^^\n',
     '  File "<doctest default[0]>", line 7, in bright_side_of_life\n    return tuple()[0]\n           ~~~~~~~^^^\n']
    *** tb_lineno: 10
 

Lib/test/test_doctest.py

@@ -2922,6 +2922,9 @@ def test_unicode(): """
         Traceback (most recent call last):
           File ...
             exec(compile(example.source, filename, "single",
+            ~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+                         compileflags, True), test.globs)
+                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
           File "<doctest foo-bär@baz[0]>", line 1, in <module>
             raise Exception('clé')
         Exception: clé

Lib/test/test_exceptions.py

@@ -2080,14 +2080,15 @@ def test_multiline_not_highlighted(self):
              """,
                 [
                     '    1 < 2 and',
+                    '    3 > 4',
                     'AssertionError',
                 ],
             ),
         ]
         for source, expected in cases:
             with self.subTest(source):
                 result = self.write_source(source)
-                self.assertEqual(result[-2:], expected)
+                self.assertEqual(result[-len(expected):], expected)
 
 
 class SyntaxErrorTests(unittest.TestCase):

Lib/test/test_repl.py

@@ -161,10 +161,11 @@ def foo(x):
         output = kill_python(p)
         self.assertEqual(p.returncode, 0)
 
-        traceback_lines = output.splitlines()[-7:-1]
+        traceback_lines = output.splitlines()[-8:-1]
         expected_lines = [
             '  File "<stdin>", line 1, in <module>',
             '    foo(0)',
+            '    ~~~^^^',
             '  File "<stdin>", line 2, in foo',
             '    1 / x',
             '    ~~^~~',

Lib/test/test_sys.py

@@ -1115,17 +1115,19 @@ def check(tracebacklimit, expected):
             b'Traceback (most recent call last):',
             b'  File "<string>", line 8, in <module>',
             b'    f2()',
+            b'    ~~^^',
             b'  File "<string>", line 6, in f2',
             b'    f1()',
+            b'    ~~^^',
             b'  File "<string>", line 4, in f1',
             b'    1 / 0',
             b'    ~~^~~',
             b'ZeroDivisionError: division by zero'
         ]
         check(10, traceback)
         check(3, traceback)
-        check(2, traceback[:1] + traceback[3:])
-        check(1, traceback[:1] + traceback[5:])
+        check(2, traceback[:1] + traceback[4:])
+        check(1, traceback[:1] + traceback[7:])
         check(0, [traceback[-1]])
         check(-1, [traceback[-1]])
         check(1<<1000, traceback)