PY-61137 Accept LiteralString if expected is a TypeVar with LiteralString as a bound

(cherry picked from commit 5de62a9e91dbfa74b5077671858f96e446e9d121)

IJ-MR-112631

GitOrigin-RevId: 829184b6a204609d67cf4c668eb1125c46fa2d84

python/python-psi-impl/src/com/jetbrains/python/psi/types/PyTypeChecker.java

@@ -234,9 +234,6 @@ public final class PyTypeChecker {
       return false;
     }
 
-    // Remove value-specific components from the actual type to make it safe to propagate
-    PyType safeActual = replaceLiteralStringWithStr(actual);
-
     final PyType substitution = context.mySubstitutions.typeVars.get(expected);
     PyType bound = expected.getBound();
     // Promote int in Type[TypeVar('T', int)] to Type[int] before checking that bounds match
@@ -245,6 +242,9 @@ public final class PyTypeChecker {
       bound = PyUnionType.union(PyTypeUtil.toStream(bound).map(toDefinition).toList());
     }
 
+    // Remove value-specific components from the actual type to make it safe to propagate
+    PyType safeActual = bound instanceof PyLiteralStringType ? actual : replaceLiteralStringWithStr(actual);
+
     Optional<Boolean> match = match(bound, safeActual, context);
     if (match.isPresent() && !match.get()) {
       return false;

python/testSrc/com/jetbrains/python/inspections/Py3TypeCheckerInspectionTest.java

@@ -1943,6 +1943,18 @@ public class Py3TypeCheckerInspectionTest extends PyInspectionTestCase {
                    """);
   }
 
+  // PY-61137
+  public void testTypeVarBoundToLiteralString() {
+    doTestByText("""
+                   from typing import TypeVar, LiteralString
+                   TLiteral = TypeVar("TLiteral", bound=LiteralString)
+                   def literal_identity(s: TLiteral) -> TLiteral:
+                       return s
+                   s: LiteralString
+                   y2 = literal_identity(s)
+                   """);
+  }
+
   // PY-62476
   public void testTypeGuardReturnTypeTreatedAsBool() {
     runWithLanguageLevel(