Merge pull request #6268 from slavapestov/missing-test-arglabel-bug

Add missing test for "Horrific simulation of Swift 3 bug with argumen…

Author: slavapestov

test/Constraints/diagnostics_swift4.swift

@@ -0,0 +1,28 @@
+// RUN: %target-typecheck-verify-swift -swift-version 4
+
+// SR-2505: "Call arguments did not match up" assertion
+
+func sr_2505(_ a: Any) {} // expected-note {{}}
+sr_2505()          // expected-error {{missing argument for parameter #1 in call}}
+sr_2505(a: 1)      // expected-error {{extraneous argument label 'a:' in call}}
+sr_2505(1, 2)      // expected-error {{extra argument in call}}
+sr_2505(a: 1, 2)   // expected-error {{extra argument in call}}
+
+struct C_2505 {
+  init(_ arg: Any) {
+  }
+}
+
+protocol P_2505 {
+}
+
+extension C_2505 {
+  init<T>(from: [T]) where T: P_2505 {
+  }
+}
+
+class C2_2505: P_2505 {
+}
+
+let c_2505 = C_2505(arg: [C2_2505()]) // expected-error {{argument labels '(arg:)' do not match any available overloads}} expected-note {{overloads for 'C_2505' exist}}
+