---

yaml
---
r: 315103
b: refs/heads/master-next
c: 9c0aad3
h: refs/heads/master
i:
  315101: 39f5599
  315099: 50c7387
  315095: 6a17b29
  315087: 937ac2a
  315071: a978159

Author: gregomni

[refs]

@@ -1,6 +1,6 @@
 ---
 refs/heads/master: 3fe9333052029c114ef816ea805c335eb1ee8a99
-refs/heads/master-next: 469e06ae2c76c12a310cdfda2173f1fafc626d97
+refs/heads/master-next: 9c0aad3737eaa19787aa6cc755620a93f5c39227
 refs/tags/osx-passed: b6b74147ef8a386f532cf9357a1bde006e552c54
 refs/tags/swift-2.2-SNAPSHOT-2015-12-01-a: 6bb18e013c2284f2b45f5f84f2df2887dc0f7dea
 refs/tags/swift-2.2-SNAPSHOT-2015-12-01-b: 66d897bfcf64a82cb9a87f5e663d889189d06d07

branches/master-next/lib/Sema/CSSimplify.cpp

@@ -2657,8 +2657,20 @@ ConstraintSystem::matchTypes(Type type1, Type type2, ConstraintKind kind,
     case ConstraintKind::Subtype:
     case ConstraintKind::Conversion:
     case ConstraintKind::ArgumentConversion:
-    case ConstraintKind::OperatorArgumentConversion:
+    case ConstraintKind::OperatorArgumentConversion: {
+      if (typeVar1) {
+        if (auto *locator = typeVar1->getImpl().getLocator()) {
+          // TODO(diagnostics): Only binding here for function types, because
+          // doing so for KeyPath types leaves the constraint system in an
+          // unexpected state for key path diagnostics should we fail.
+          if (locator->isLastElement(ConstraintLocator::KeyPathType) &&
+              type2->is<AnyFunctionType>())
+            return matchTypesBindTypeVar(typeVar1, type2, kind, flags, locator,
+                                         formUnsolvedResult);
+        }
+      }
       return formUnsolvedResult();
+    }
 
     case ConstraintKind::OpaqueUnderlyingType:
     case ConstraintKind::ApplicableFunction:
@@ -5590,22 +5602,6 @@ ConstraintSystem::simplifyKeyPathConstraint(Type keyPathTy,
       return SolutionKind::Error;
   }
 
-  // If we have nothing else, and there's another constraint on our keyPathTy
-  // type variable that's some sort of conversion to a function type, use that
-  // constraint's second type.
-  if (keyPathTy->isTypeVariableOrMember()) {
-    for (auto constraint : getActiveConstraints()) {
-      if (constraint.getKind() > ConstraintKind::OperatorArgumentConversion)
-        continue;
-      if (constraint.getFirstType().getPointer() == keyPathTy.getPointer()) {
-        auto otherType = constraint.getSecondType();
-        if (otherType->is<FunctionType>() &&
-            !tryMatchRootAndValueFromType(otherType))
-          return SolutionKind::Error;
-      }
-    }
-  }
-
   // See if we resolved overloads for all the components involved.
   enum {
     ReadOnly,
@@ -5736,10 +5732,7 @@ ConstraintSystem::simplifyKeyPathConstraint(Type keyPathTy,
 
   auto loc = locator.getBaseLocator();
   if (definitelyFunctionType) {
-    Type fnType =
-        FunctionType::get({AnyFunctionType::Param(rootTy)}, valueTy,
-                          AnyFunctionType::ExtInfo().withThrows(false));
-    return matchTypes(keyPathTy, fnType, ConstraintKind::Bind, subflags, loc);
+    return SolutionKind::Solved;
   } else if (!anyComponentsUnresolved ||
              (definitelyKeyPathType && capability == ReadOnly)) {
     auto resolvedKPTy =