From cffa5157a75f54a631e155c4ee3ba1d5d995b890 Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Fri, 2 Jun 2023 16:12:25 -0700
Subject: [PATCH] Ensure we don't overwrite computed CouldContainTypeVariables
 in new optimization

---
 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 72d7f692f9b43..f2f0aaff9c59a 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -18800,8 +18800,12 @@ 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);
             }