---

yaml
---
r: 343550
b: refs/heads/master-rebranch
c: 5a1f06a
h: refs/heads/master

Author: theblixguy

[refs]

@@ -1455,7 +1455,7 @@ refs/tags/swift-DEVELOPMENT-SNAPSHOT-2019-08-02-a: ddd2b2976aa9bfde5f20fe37f6bd2
 refs/tags/swift-DEVELOPMENT-SNAPSHOT-2019-08-03-a: 171cc166f2abeb5ca2a4003700a8a78a108bd300
 refs/heads/benlangmuir-patch-1: baaebaf39d52f3bf36710d4fe40cf212e996b212
 refs/heads/i-do-redeclare: 8c4e6d5de5c1e3f0a2cedccf319df713ea22c48e
-refs/heads/master-rebranch: 666c000607214d1fb42b4157e468e78b9d0bb779
+refs/heads/master-rebranch: 5a1f06a1ef2350a7cd0b656f72b6bae4432fa630
 refs/heads/rdar-53901732: 9bd06af3284e18a109cdbf9aa59d833b24eeca7b
 refs/heads/revert-26776-subst-always-returns-a-type: 1b8e18fdd391903a348970a4c848995d4cdd789c
 refs/heads/tensorflow-merge: 8b854f62f80d4476cb383d43c4aac2001dde3cec

branches/master-rebranch/lib/Sema/CSDiagnostics.cpp

@@ -2452,8 +2452,10 @@ bool ContextualFailure::tryProtocolConformanceFixIt(
   // If the protocol requires a class & we don't have one (maybe the context
   // is a struct), then bail out instead of offering a broken fix-it later on.
   auto requiresClass = false;
+  ExistentialLayout layout;
   if (unwrappedToType->isExistentialType()) {
-    requiresClass = unwrappedToType->getExistentialLayout().requiresClass();
+    layout = unwrappedToType->getExistentialLayout();
+    requiresClass = layout.requiresClass();
   }
   if (requiresClass && !FromType->is<ClassType>()) {
     return false;
@@ -2469,23 +2471,20 @@ bool ContextualFailure::tryProtocolConformanceFixIt(
   diagnostic.flush();
 
   // Let's build a list of protocols that the contextual type does not
-  // conform to. We will start by first checking if we have a protocol
-  // composition type and add all the individual types that the context
-  // does not conform to.
+  // conform to.
   SmallVector<std::string, 8> missingProtoTypeStrings;
-  if (auto compositionTy = unwrappedToType->getAs<ProtocolCompositionType>()) {
-    for (auto memberTy : compositionTy->getMembers()) {
-      auto protocol = memberTy->getAnyNominal()->getSelfProtocolDecl();
-      if (!getTypeChecker().conformsToProtocol(
-              FromType, protocol, getDC(),
-              ConformanceCheckFlags::InExpression)) {
-        missingProtoTypeStrings.push_back(memberTy->getString());
-      }
+  for (auto protocol : layout.getProtocols()) {
+    if (!getTypeChecker().conformsToProtocol(
+            FromType, protocol->getDecl(), getDC(),
+            ConformanceCheckFlags::InExpression)) {
+      missingProtoTypeStrings.push_back(protocol->getString());
     }
-    // If we don't conform to all of the protocols in the composition, then
-    // store the composition type only. This is because we need to append
-    // 'Foo & Bar' instead of 'Foo, Bar' in order to match the written type.
-    if (missingProtoTypeStrings.size() == compositionTy->getMembers().size()) {
+  }
+
+  // If we have a protocol composition type and we don't conform to all
+  // the protocols of the composition, then store the composition directly.
+  if (auto compositionTy = unwrappedToType->getAs<ProtocolCompositionType>()) {
+    if (compositionTy->getMembers().size() == missingProtoTypeStrings.size()) {
       missingProtoTypeStrings = {compositionTy->getString()};
     }
   }