[3.13] gh-82378 fix sys.tracebacklimit in pyrepl, approach 2 (GH-123062) (#123252)

Make sure that pyrepl uses the same logic for sys.tracebacklimit as both
the basic repl and the standard sys.excepthook
(cherry picked from commit 63603bca35)

Lib/_pyrepl/console.py

@@ -164,8 +164,13 @@ def __init__(
     def showsyntaxerror(self, filename=None, **kwargs):
         super().showsyntaxerror(filename=filename, **kwargs)
 
-    def showtraceback(self):
-        super().showtraceback(colorize=self.can_colorize)
+    def _excepthook(self, typ, value, tb):
+        import traceback
+        lines = traceback.format_exception(
+                typ, value, tb,
+                colorize=self.can_colorize,
+                limit=traceback.BUILTIN_EXCEPTION_LIMIT)
+        self.write(''.join(lines))
 
     def runsource(self, source, filename="<input>", symbol="single"):
         try:

Lib/code.py

@@ -107,17 +107,16 @@ def showsyntaxerror(self, filename=None, **kwargs):
         The output is written by self.write(), below.
 
         """
-        colorize = kwargs.pop('colorize', False)
         try:
             typ, value, tb = sys.exc_info()
             if filename and issubclass(typ, SyntaxError):
                 value.filename = filename
             source = kwargs.pop('source', "")
-            self._showtraceback(typ, value, None, colorize, source)
+            self._showtraceback(typ, value, None, source)
         finally:
             typ = value = tb = None
 
-    def showtraceback(self, **kwargs):
+    def showtraceback(self):
         """Display the exception that just occurred.
 
         We remove the first stack item because it is our own code.
@@ -125,14 +124,13 @@ def showtraceback(self, **kwargs):
         The output is written by self.write(), below.
 
         """
-        colorize = kwargs.pop('colorize', False)
         try:
             typ, value, tb = sys.exc_info()
-            self._showtraceback(typ, value, tb.tb_next, colorize, '')
+            self._showtraceback(typ, value, tb.tb_next, '')
         finally:
             typ = value = tb = None
 
-    def _showtraceback(self, typ, value, tb, colorize, source):
+    def _showtraceback(self, typ, value, tb, source):
         sys.last_type = typ
         sys.last_traceback = tb
         value = value.with_traceback(tb)
@@ -143,9 +141,7 @@ def _showtraceback(self, typ, value, tb, colorize, source):
             value.text = lines[value.lineno - 1]
         sys.last_exc = sys.last_value = value = value.with_traceback(tb)
         if sys.excepthook is sys.__excepthook__:
-            lines = traceback.format_exception(typ, value, tb,
-                                               colorize=colorize)
-            self.write(''.join(lines))
+            self._excepthook(typ, value, tb)
         else:
             # If someone has set sys.excepthook, we let that take precedence
             # over self.write
@@ -162,6 +158,12 @@ def _showtraceback(self, typ, value, tb, colorize, source):
                 print('Original exception was:', file=sys.stderr)
                 sys.__excepthook__(typ, value, tb)
 
+    def _excepthook(self, typ, value, tb):
+        # This method is being overwritten in
+        # _pyrepl.console.InteractiveColoredConsole
+        lines = traceback.format_exception(typ, value, tb)
+        self.write(''.join(lines))
+
     def write(self, data):
         """Write a string.
 

Lib/test/test_pyrepl/test_pyrepl.py

@@ -1020,7 +1020,7 @@ def test_dumb_terminal_exits_cleanly(self):
         env.update({"TERM": "dumb"})
         output, exit_code = self.run_repl("exit()\n", env=env)
         self.assertEqual(exit_code, 0)
-        self.assertIn("warning: can\'t use pyrepl", output)
+        self.assertIn("warning: can't use pyrepl", output)
         self.assertNotIn("Exception", output)
         self.assertNotIn("Traceback", output)
 
@@ -1114,6 +1114,38 @@ def test_correct_filename_in_syntaxerrors(self):
         self.assertIn("IndentationError: unexpected indent", output)
         self.assertIn("<python-input-0>", output)
 
+    @force_not_colorized
+    def test_proper_tracebacklimit(self):
+        env = os.environ.copy()
+        for set_tracebacklimit in [True, False]:
+            commands = ("import sys\n" +
+                        ("sys.tracebacklimit = 1\n" if set_tracebacklimit else "") +
+                        "def x1(): 1/0\n\n"
+                        "def x2(): x1()\n\n"
+                        "def x3(): x2()\n\n"
+                        "x3()\n"
+                        "exit()\n")
+
+            for basic_repl in [True, False]:
+                if basic_repl:
+                    env["PYTHON_BASIC_REPL"] = "1"
+                else:
+                    env.pop("PYTHON_BASIC_REPL", None)
+                with self.subTest(set_tracebacklimit=set_tracebacklimit,
+                                  basic_repl=basic_repl):
+                    output, exit_code = self.run_repl(commands, env=env)
+                    if "can't use pyrepl" in output:
+                        self.skipTest("pyrepl not available")
+                    self.assertIn("in x1", output)
+                    if set_tracebacklimit:
+                        self.assertNotIn("in x2", output)
+                        self.assertNotIn("in x3", output)
+                        self.assertNotIn("in <module>", output)
+                    else:
+                        self.assertIn("in x2", output)
+                        self.assertIn("in x3", output)
+                        self.assertIn("in <module>", output)
+
     def run_repl(
         self,
         repl_input: str | list[str],

Misc/NEWS.d/next/Library/2024-07-31-14-55-41.gh-issue-82378.eZvYmR.rst

@@ -0,0 +1,2 @@
+Make sure that the new :term:`REPL` interprets :data:`sys.tracebacklimit` in
+the same way that the classic REPL did.