Fix false-negative for used-before-assignment with postponed evaluation in function defs (#10482) (#10483)

pylint-backport-bot[bot] · cdce8p · web-flow · commit cef60cc3a557 · 2025-08-07T09:56:00.000Z
(cherry picked from commit d363fca) Co-authored-by: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
diff --git a/doc/whatsnew/fragments/10482.false_negative b/doc/whatsnew/fragments/10482.false_negative
@@ -0,0 +1,3 @@
+Fix false-negative for ``used-before-assignment`` with ``from __future__ import annotations`` in function definitions.
+
+Refs #10482
diff --git a/pylint/checkers/variables.py b/pylint/checkers/variables.py
@@ -1949,7 +1949,17 @@ def _check_consumer(
                 # and unevaluated annotations inside a function body
                 if not (
                     self._postponed_evaluation_enabled
-                    and isinstance(stmt, (nodes.AnnAssign, nodes.FunctionDef))
+                    and (
+                        isinstance(stmt, nodes.AnnAssign)
+                        or (
+                            isinstance(stmt, nodes.FunctionDef)
+                            and node
+                            not in {
+                                *(stmt.args.defaults or ()),
+                                *(stmt.args.kw_defaults or ()),
+                            }
+                        )
+                    )
                 ) and not (
                     isinstance(stmt, nodes.AnnAssign)
                     and utils.get_node_first_ancestor_of_type(stmt, nodes.FunctionDef)

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	+Fix false-negative for ``used-before-assignment`` with ``from __future__ import annotations`` in function definitions.
	`2`	`+`
	`3`	`+Refs #10482`