Synthetic extensions wins against top-level extension.

compiler/testData/diagnostics/tests/resolve/priority/syntheticPropertiesVsExtensions.kt

@@ -0,0 +1,31 @@
+// !CHECK_TYPE
+// !DIAGNOSTICS: -UNUSED_EXPRESSION -UNUSED_PARAMETER -UNUSED_VARIABLE
+
+// FILE: A.java
+public class A {
+    public A getFoo() { return 3; }
+}
+
+// FILE: 1.kt
+
+private val A.foo: Int get() = 4
+
+fun test(a: A) {
+    a.foo checkType { _<A>() }
+    with(a) {
+        foo checkType { _<A>() }
+    }
+}
+
+class B {
+    private val A.foo: B get() = this@B
+
+    fun test(a: A) {
+        a.foo checkType { _<B>() } // todo
+        with(a) {
+            foo checkType { _<B>() } // todo
+        }
+    }
+}
+
+fun <T, R> with(receiver: T, f: T.() -> R): R = receiver.f()

compiler/testData/diagnostics/tests/resolve/priority/syntheticPropertiesVsExtensions.txt

@@ -0,0 +1,22 @@
+package
+
+private val A.foo: kotlin.Int
+public fun test(/*0*/ a: A): kotlin.Unit
+public fun </*0*/ T, /*1*/ R> with(/*0*/ receiver: T, /*1*/ f: T.() -> R): R
+
+public open class A {
+    public constructor A()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open fun getFoo(): A!
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class B {
+    public constructor B()
+    private final val A.foo: B
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public final fun test(/*0*/ a: A): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/resolve/priority/syntheticPropertiesVsMembers.kt

@@ -0,0 +1,38 @@
+// !CHECK_TYPE
+// !DIAGNOSTICS: -UNUSED_EXPRESSION -UNUSED_PARAMETER -UNUSED_VARIABLE
+
+// FILE: A.java
+public class A {
+    public A getFoo() { return 3; }
+}
+
+// FILE: B.java
+public class B {
+    public B getFoo() { return ""; }
+}
+
+// FILE: 1.kt
+class C(val foo: C)
+
+fun test(a: A, b: B, c: C) {
+    with(a) {
+        with(b) {
+            foo checkType { _<B>() }
+        }
+        foo checkType { _<A>() }
+    }
+
+    with(a) {
+        with(c) {
+            foo checkType { _<C>() }
+        }
+    }
+
+    with(c) {
+        with(a) {
+            foo checkType { _<C>() } // todo
+        }
+    }
+}
+
+fun <T, R> with(receiver: T, f: T.() -> R): R = receiver.f()

compiler/testData/diagnostics/tests/resolve/priority/syntheticPropertiesVsMembers.txt

@@ -0,0 +1,28 @@
+package
+
+public fun test(/*0*/ a: A, /*1*/ b: B, /*2*/ c: C): kotlin.Unit
+public fun </*0*/ T, /*1*/ R> with(/*0*/ receiver: T, /*1*/ f: T.() -> R): R
+
+public open class A {
+    public constructor A()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open fun getFoo(): A!
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public open class B {
+    public constructor B()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open fun getFoo(): B!
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class C {
+    public constructor C(/*0*/ foo: C)
+    public final val foo: C
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}