From e3c5209ae25d13a315e95b1fd35de8baa6ed479c Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Mon, 5 Jun 2023 15:31:19 -0700
Subject: [PATCH] Ensure we don't overwrite computed CouldContainTypeVariables
 in new optimization (#54507)

---
 src/compiler/checker.ts | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index d387872ca27..153cc6fb644 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -18801,8 +18801,12 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 // If none of the type arguments for the outer type parameters contain type variables, it follows
                 // that the instantiated type doesn't reference type variables.
                 if (result.flags & TypeFlags.ObjectFlagsType && !((result as ObjectFlagsType).objectFlags & ObjectFlags.CouldContainTypeVariablesComputed)) {
-                    (result as ObjectFlagsType).objectFlags |= ObjectFlags.CouldContainTypeVariablesComputed |
-                        (some(typeArguments, couldContainTypeVariables) ? ObjectFlags.CouldContainTypeVariables : 0);
+                    const resultCouldContainTypeVariables = some(typeArguments, couldContainTypeVariables);
+                    // The above check may have caused the result's objectFlags to update if the result is referenced via typeArguments.
+                    if (!((result as ObjectFlagsType).objectFlags & ObjectFlags.CouldContainTypeVariablesComputed)) {
+                        (result as ObjectFlagsType).objectFlags |= ObjectFlags.CouldContainTypeVariablesComputed |
+                            (resultCouldContainTypeVariables ? ObjectFlags.CouldContainTypeVariables : 0);
+                    }
                 }
                 target.instantiations.set(id, result);
             }