From 9cad4bae6b6a57b5ef622e97b63a8785fcb2c486 Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Mon, 5 Jun 2023 22:37:20 +0000
Subject: [PATCH] Cherry-pick PR #54507 into release-5.1

Component commits:
cffa5157a7 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 0715f58e71429..59e5c3e8aee45 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -18768,8 +18768,12 @@ 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);
             }