Fix logic error introduced in #30334

Author: ahejlsberg

src/compiler/checker.ts

@@ -14617,9 +14617,11 @@ namespace ts {
                                 const candidate = propagationType || source;
                                 // We make contravariant inferences only if we are in a pure contravariant position,
                                 // i.e. only if we have not descended into a bivariant position.
-                                if (contravariant && !bivariant && !contains(inference.contraCandidates, candidate)) {
-                                    inference.contraCandidates = append(inference.contraCandidates, candidate);
-                                    inference.inferredType = undefined;
+                                if (contravariant && !bivariant) {
+                                    if (!contains(inference.contraCandidates, candidate)) {
+                                        inference.contraCandidates = append(inference.contraCandidates, candidate);
+                                        inference.inferredType = undefined;
+                                    }
                                 }
                                 else if (!contains(inference.candidates, candidate)) {
                                     inference.candidates = append(inference.candidates, candidate);