Merge pull request #69939 from xedin/issue-69936

[ConstraintSystem] Key path literals with completion tokens should be…

Author: xedin

lib/Sema/CSBindings.cpp

@@ -641,14 +641,15 @@ void BindingSet::finalize(
           updatedBindings.insert(
               {keyPathTy, AllowedBindingKind::Exact, keyPathLoc});
         } else if (CS.shouldAttemptFixes()) {
+          auto fixedRootTy = CS.getFixedType(rootTy);
           // If key path is structurally correct and has a resolved root
           // type, let's promote the fallback type into a binding because
           // root would have been inferred from explicit type already and
           // it's benefitial for diagnostics to assign a non-placeholder
           // type to key path literal to propagate root/value to the context.
           if (!keyPath->hasSingleInvalidComponent() &&
               (keyPath->getParsedRoot() ||
-               !CS.getFixedType(rootTy)->isTypeVariableOrMember())) {
+               (fixedRootTy && !fixedRootTy->isTypeVariableOrMember()))) {
             auto fallback = llvm::find_if(Defaults, [](const auto &entry) {
               return entry.second->getKind() == ConstraintKind::FallbackType;
             });

lib/Sema/ConstraintSystem.cpp

@@ -7470,8 +7470,7 @@ ConstraintSystem::inferKeyPathLiteralCapability(KeyPathExpr *keyPath) {
       break;
 
     case KeyPathExpr::Component::Kind::CodeCompletion: {
-      capability = KeyPathCapability::ReadOnly;
-      break;
+      return fail();
     }
     case KeyPathExpr::Component::Kind::Property:
     case KeyPathExpr::Component::Kind::Subscript:

test/IDE/complete_issue-69936.swift

@@ -0,0 +1,13 @@
+// RUN: %batch-code-completion
+
+struct Test {
+  var currentHeight: Int
+
+  func subscribeToKeyboardEvents() {
+    objectAndKeyPath(object: self, keyPath: \.#^COMPLETE^#)
+  }
+}
+
+func objectAndKeyPath<Root, Input>(object: Root, keyPath: WritableKeyPath<Root, Input>) {}
+
+// COMPLETE: Decl[InstanceVar]/CurrNominal:      currentHeight[#Int#]; name=currentHeight