Issue #27213: Fixed different issues with reworked CALL_FUNCTION* opcodes.

* BUILD_TUPLE_UNPACK and BUILD_MAP_UNPACK_WITH_CALL no longer generated with
  single tuple or dict.
* Restored more informative error messages for incorrect var-positional and
  var-keyword arguments.
* Removed code duplications in _PyEval_EvalCodeWithName().
* Removed redundant runtime checks and parameters in _PyStack_AsDict().
* Added a workaround and enabled previously disabled test in test_traceback.
* Removed dead code from the dis module.

3 files changed, 11 insertions, 12 deletions

diff --git a/Lib/dis.py b/Lib/dis.py
index e958c8a..3a706be 100644
--- a/Lib/dis.py
+++ b/Lib/dis.py
@@ -314,8 +314,6 @@ def _get_instructions_bytes(code, varnames=None, names=None, constants=None,
                 argrepr = argval
             elif op in hasfree:
                 argval, argrepr = _get_name_info(arg, cells)
-            elif op in hasnargs: # unused
-                argrepr = "%d positional, %d keyword pair" % (arg%256, arg//256)
         yield Instruction(opname[op], op,
                           arg, argval, argrepr,
                           offset, starts_line, is_jump_target)
diff --git a/Lib/test/test_extcall.py b/Lib/test/test_extcall.py
index 55f1393..5eea379 100644
--- a/Lib/test/test_extcall.py
+++ b/Lib/test/test_extcall.py
@@ -118,7 +118,7 @@ Verify clearing of SF bug #733667
     >>> g(*Nothing())
     Traceback (most recent call last):
       ...
-    TypeError: 'Nothing' object is not iterable
+    TypeError: g() argument after * must be an iterable, not Nothing
 
     >>> class Nothing:
     ...     def __len__(self): return 5
@@ -127,7 +127,7 @@ Verify clearing of SF bug #733667
     >>> g(*Nothing())
     Traceback (most recent call last):
       ...
-    TypeError: 'Nothing' object is not iterable
+    TypeError: g() argument after * must be an iterable, not Nothing
 
     >>> class Nothing():
     ...     def __len__(self): return 5
@@ -231,32 +231,34 @@ What about willful misconduct?
     >>> h(*h)
     Traceback (most recent call last):
       ...
-    TypeError: 'function' object is not iterable
+    TypeError: h() argument after * must be an iterable, not function
 
     >>> dir(*h)
     Traceback (most recent call last):
       ...
-    TypeError: 'function' object is not iterable
+    TypeError: dir() argument after * must be an iterable, not function
 
     >>> None(*h)
     Traceback (most recent call last):
       ...
-    TypeError: 'function' object is not iterable
+    TypeError: NoneType object argument after * must be an iterable, \
+not function
 
     >>> h(**h)
     Traceback (most recent call last):
       ...
-    TypeError: 'function' object is not a mapping
+    TypeError: h() argument after ** must be a mapping, not function
 
     >>> dir(**h)
     Traceback (most recent call last):
       ...
-    TypeError: 'function' object is not a mapping
+    TypeError: dir() argument after ** must be a mapping, not function
 
     >>> None(**h)
     Traceback (most recent call last):
       ...
-    TypeError: 'function' object is not a mapping
+    TypeError: NoneType object argument after ** must be a mapping, \
+not function
 
     >>> dir(b=1, **{'b': 1})
     Traceback (most recent call last):
diff --git a/Lib/test/test_traceback.py b/Lib/test/test_traceback.py
index 037d883..ac067bf 100644
--- a/Lib/test/test_traceback.py
+++ b/Lib/test/test_traceback.py
@@ -304,7 +304,6 @@ class TracebackFormatTests(unittest.TestCase):
         ])
 
     # issue 26823 - Shrink recursive tracebacks
-    @unittest.skipIf(True, "FIXME: test broken, see issue #28050")
     def _check_recursive_traceback_display(self, render_exc):
         # Always show full diffs when this test fails
         # Note that rearranging things may require adjusting
@@ -353,7 +352,7 @@ class TracebackFormatTests(unittest.TestCase):
 
         # Check the recursion count is roughly as expected
         rec_limit = sys.getrecursionlimit()
-        self.assertIn(int(re.search(r"\d+", actual[-2]).group()), range(rec_limit-50, rec_limit))
+        self.assertIn(int(re.search(r"\d+", actual[-2]).group()), range(rec_limit-60, rec_limit))
 
         # Check a known (limited) number of recursive invocations
         def g(count=10):