Merge pull request #10703 from Microsoft/fixSignatureCache

Fix call signature caching

Author: ahejlsberg

src/compiler/checker.ts

@@ -143,6 +143,7 @@ namespace ts {
 
         const anySignature = createSignature(undefined, undefined, undefined, emptyArray, anyType, /*typePredicate*/ undefined, 0, /*hasRestParameter*/ false, /*hasLiteralTypes*/ false);
         const unknownSignature = createSignature(undefined, undefined, undefined, emptyArray, unknownType, /*typePredicate*/ undefined, 0, /*hasRestParameter*/ false, /*hasLiteralTypes*/ false);
+        const resolvingSignature = createSignature(undefined, undefined, undefined, emptyArray, anyType, /*typePredicate*/ undefined, 0, /*hasRestParameter*/ false, /*hasLiteralTypes*/ false);
 
         const enumNumberIndexInfo = createIndexInfo(stringType, /*isReadonly*/ true);
 
@@ -12229,10 +12230,10 @@ namespace ts {
             // or that a different candidatesOutArray was passed in. Therefore, we need to redo the work
             // to correctly fill the candidatesOutArray.
             const cached = links.resolvedSignature;
-            if (cached && cached !== anySignature && !candidatesOutArray) {
+            if (cached && cached !== resolvingSignature && !candidatesOutArray) {
                 return cached;
             }
-            links.resolvedSignature = anySignature;
+            links.resolvedSignature = resolvingSignature;
             const result = resolveSignature(node, candidatesOutArray);
             // If signature resolution originated in control flow type analysis (for example to compute the
             // assigned type in a flow assignment) we don't cache the result as it may be based on temporary
@@ -12244,7 +12245,7 @@ namespace ts {
         function getResolvedOrAnySignature(node: CallLikeExpression) {
             // If we're already in the process of resolving the given signature, don't resolve again as
             // that could cause infinite recursion. Instead, return anySignature.
-            return getNodeLinks(node).resolvedSignature === anySignature ? anySignature : getResolvedSignature(node);
+            return getNodeLinks(node).resolvedSignature === resolvingSignature ? resolvingSignature : getResolvedSignature(node);
         }
 
         function getInferredClassType(symbol: Symbol) {