Add test cases for Bugzilla Issue 19408

Author: limepoutine

compiler/test/fail_compilation/issue19408.d

@@ -0,0 +1,45 @@
+/*
+TEST_OUTPUT:
+---
+fail_compilation/issue19408.d(43): Error: function `issue19408.Infidel!(S).Infidel.get` is not `nothrow`
+fail_compilation/issue19408.d(13):        which calls `this(this) { if (this.x > 0) throw new Exception19408; else this.x = 1; }`
+fail_compilation/issue19408.d(42): Error: delegate `issue19408.failCompile.__lambda_L42_C18` may throw but is marked as `nothrow`
+---
+*/
+
+struct Infidel(T)
+{
+    T value;
+    T get() { return value; } // returns a copy
+}
+
+class Exception19408 : Exception
+{
+    this() { super("fail"); }
+}
+
+void assertThrown(void delegate() nothrow dg)
+{
+    dg();
+}
+
+void failCompile()
+{
+    static struct S
+    {
+        int x;
+        this(this)
+        {
+            if (x > 0) throw new Exception19408();
+            else x = 1;
+        }
+    }
+
+    S s;
+    auto sneak = Infidel!S(s);
+
+    // shouldn't compile
+    assertThrown(() nothrow {
+        auto x = sneak.get();
+    });
+}

compiler/test/runnable/issue19408.d

@@ -0,0 +1,30 @@
+struct Infidel(T)
+{
+    T value;
+    T get() { return value; } // returns a copy
+}
+
+void main()
+{
+    static struct S
+    {
+        int x;
+        this(this)
+        {
+            if (x > 0) throw new Exception("fail");
+            else x = 1;
+        }
+    }
+
+    // passes, cannot nothrow-copy
+    static assert(!is(typeof(() nothrow { S* x; union U { S x; } U u = U(*x); })));
+
+    // passes, copy may throw
+    static assert(is(typeof(() { S* x; union U { S x; } U u = U(*x); })));
+
+    S s;
+    auto sneak = Infidel!S(s); // won't throw here, s.x was 0
+
+    // should pass
+    static assert(!is(typeof(() nothrow { auto x = sneak.get(); })));
+}