Unifier: Fix matching of callable references with expression receivers

#KT-21334 Fixed

idea/ide-common/src/org/jetbrains/kotlin/idea/util/psi/patternMatching/KotlinPsiUnifier.kt

@@ -49,6 +49,7 @@ import org.jetbrains.kotlin.resolve.scopes.receivers.Receiver
 import org.jetbrains.kotlin.resolve.source.getPsi
 import org.jetbrains.kotlin.types.*
 import org.jetbrains.kotlin.types.checker.KotlinTypeChecker
+import org.jetbrains.kotlin.types.expressions.DoubleColonLHS
 import org.jetbrains.kotlin.types.expressions.OperatorConventions
 import java.util.*
 
@@ -458,10 +459,14 @@ class KotlinPsiUnifier(
                    && ((parent.operationToken as KtToken) in OperatorConventions.INCREMENT_OPERATIONS)
         }
 
-        private fun matchCallableReferences(e1: KtCallableReferenceExpression, e2: KtCallableReferenceExpression): Boolean {
+        private fun KtCallableReferenceExpression.hasExpressionReceiver(): Boolean =
+                bindingContext[BindingContext.DOUBLE_COLON_LHS, receiverExpression] is DoubleColonLHS.Expression
+
+        private fun matchCallableReferences(e1: KtCallableReferenceExpression, e2: KtCallableReferenceExpression): Status? {
+            if (e1.hasExpressionReceiver() || e2.hasExpressionReceiver()) return null
             val d1 = e1.bindingContext[BindingContext.REFERENCE_TARGET, e1.callableReference]
             val d2 = e2.bindingContext[BindingContext.REFERENCE_TARGET, e2.callableReference]
-            return matchDescriptors(d1, d2)
+            return if (matchDescriptors(d1, d2)) MATCHED else UNMATCHED
         }
 
         private fun matchThisExpressions(e1: KtThisExpression, e2: KtThisExpression): Boolean {
@@ -748,7 +753,7 @@ class KotlinPsiUnifier(
                     UNMATCHED
 
                 e1 is KtCallableReferenceExpression && e2 is KtCallableReferenceExpression ->
-                    if (matchCallableReferences(e1, e2)) MATCHED else UNMATCHED
+                    matchCallableReferences(e1, e2)
 
                 e1 is KtThisExpression && e2 is KtThisExpression -> if (matchThisExpressions(e1, e2)) MATCHED else UNMATCHED
 

idea/testData/unifier/equivalence/expressions/callableReferences/expressionReceivers.kt

@@ -0,0 +1,14 @@
+public fun String.bar() = ""
+
+fun foo() {
+    val f = if (1 < 2) {
+        <selection>"abc"::bar</selection>
+    } else {
+        "def"::bar
+    }
+    val ff = if (1 < 2) {
+        ("abc")::bar
+    } else {
+        ("def")::bar
+    }
+}

idea/testData/unifier/equivalence/expressions/callableReferences/expressionReceivers.kt.match

@@ -0,0 +1,3 @@
+"abc"::bar
+
+("abc")::bar

idea/tests/org/jetbrains/kotlin/psi/patternMatching/PsiUnifierTestGenerated.java

@@ -351,6 +351,12 @@ public class PsiUnifierTestGenerated extends AbstractPsiUnifierTest {
                     doTest(fileName);
                 }
 
+                @TestMetadata("expressionReceivers.kt")
+                public void testExpressionReceivers() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("idea/testData/unifier/equivalence/expressions/callableReferences/expressionReceivers.kt");
+                    doTest(fileName);
+                }
+
                 @TestMetadata("functionRefRuntime.kt")
                 public void testFunctionRefRuntime() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("idea/testData/unifier/equivalence/expressions/callableReferences/functionRefRuntime.kt");