signature: Fix handling of rlcompleter as intermediate solution

The rlcompleter module calls inspect.signature which breaks
the multi-signatures of the signature C module.

The __signature__ attribute should no longer be used anyway
and people should use get_signature(), instead. But before we
evict this attribute, this patch fixes the problem, temporarily.

[ChangeLog][PySide6] Python 3.10 and up have an incompatibility
to the __signature__ attribute. This temporary patch fixes this
until final removal of that attribute.

Change-Id: Ic08d551cd388e6b3b29eb4694427a7202a4272b4
Fixes: PYSIDE-2101
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
(cherry picked from commit 95e9f8fd675c6e4f1eeabe9337a7cb9c1e3b4456)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 26 insertions, 0 deletions

diff --git a/sources/pyside6/PySide6/support/deprecated.py b/sources/pyside6/PySide6/support/deprecated.py
index f215f2ff5..449a5d2f0 100644
--- a/sources/pyside6/PySide6/support/deprecated.py
+++ b/sources/pyside6/PySide6/support/deprecated.py
@@ -18,6 +18,8 @@ PYSIDE-1735: This is also used now for missing other functions (overwriting __or
              in Qt.(Keyboard)Modifier).
 """
 
+import inspect
+import sys
 import warnings
 from textwrap import dedent
 
@@ -68,4 +70,28 @@ def fix_for_QtCore(QtCore):
     Qt.Modifier.__add__ = func_add
     Qt.Modifier.__radd__ = func_add
 
+    # PYSIDE-2101: Fix rlcompleter until we evict the __signature__ attribute
+    apply_rlcompleter_patch()
+
+
+def apply_rlcompleter_patch():
+
+    def _callable_postfix(self, val, word):
+        if callable(val):
+            word += "("
+            try:
+                if not inspect.signature(val).parameters:
+                    word += ")"
+            except ValueError:
+                pass
+            # PYSIDE-2101: this line is added because inspect.signature cannot handle lists
+            except TypeError:
+                pass
+
+        return word
+
+    if sys.version_info[:2] >= (3, 10):
+        from rlcompleter import Completer
+        Completer._callable_postfix = _callable_postfix
+
 # eof