Fix incorrect consider-using-ternary when condition is inferable as False

ChangeLog

@@ -11,6 +11,10 @@ Release date: TBA
 ..
   Put new features here and also in 'doc/whatsnew/2.12.rst'
 
+* Fix ``simplify-boolean-expression`` when condition can be inferred as False.
+
+  Closes #5200
+
 * Fix exception when pyreverse parses ``property function`` of a class.
 
 * Add an optional extension ``consider-using-any-or-all`` : Emitted when a ``for`` loop only

doc/whatsnew/2.12.rst

@@ -64,6 +64,10 @@ Extensions
 Other Changes
 =============
 
+* Fix ``simplify-boolean-expression`` when condition can be inferred as False.
+
+  Closes #5200
+
 * Fix exception when pyreverse parses ``property function`` of a class.
 
 * Improve and flatten ``unused-wildcard-import`` message

pylint/checkers/refactoring/refactoring_checker.py

@@ -1393,10 +1393,10 @@ def visit_return(self, node: nodes.Return) -> None:
             return
 
         inferred_truth_value = utils.safe_infer(truth_value)
-        if inferred_truth_value in (None, astroid.Uninferable):
+        if inferred_truth_value is None or inferred_truth_value == astroid.Uninferable:
             truth_boolean_value = True
         else:
-            truth_boolean_value = truth_value.bool_value()
+            truth_boolean_value = inferred_truth_value.bool_value()
 
         if truth_boolean_value is False:
             message = "simplify-boolean-expression"

tests/functional/t/ternary.py

@@ -31,3 +31,9 @@ def func4():
     """"Using a Name as a condition but still emits"""
     truth_value = 42
     return condition and truth_value or false_value # [consider-using-ternary]
+
+
+def func5():
+    """"Using a Name that infers to False as a condition does not emit"""
+    falsy_value = False
+    return condition and falsy_value or false_value # [simplify-boolean-expression]

tests/functional/t/ternary.txt

@@ -5,3 +5,4 @@ consider-using-ternary:19:0::Consider using ternary ('greater' if SOME_VALUE1 >
 consider-using-ternary:20:0::Consider using ternary ('both' if SOME_VALUE2 > 4 and SOME_VALUE3 else 'not')
 simplify-boolean-expression:23:0::Boolean expression may be simplified to SOME_VALUE2
 consider-using-ternary:33:4:func4:Consider using ternary (truth_value if condition else false_value)
+simplify-boolean-expression:39:4:func5:Boolean expression may be simplified to false_value