Merge pull request #4589 from 9rnsr/fix13920

Issue 13920 - DMD crash when trying to set a delegate from __traits(getOverloads)

src/expression.c

@@ -8059,9 +8059,10 @@ Expression *DelegateExp::semantic(Scope *sc)
     e1 = e1->semantic(sc);
     type = new TypeDelegate(func->type);
     type = type->semantic(loc, sc);
-    AggregateDeclaration *ad = func->toParent()->isAggregateDeclaration();
-    if (func->needThis())
-        e1 = getRightThis(loc, sc, ad, e1, func);
+    FuncDeclaration *f = func->toAliasFunc();
+    AggregateDeclaration *ad = f->toParent()->isAggregateDeclaration();
+    if (f->needThis())
+        e1 = getRightThis(loc, sc, ad, e1, f);
     if (ad && ad->isClassDeclaration() && ad->type != e1->type)
     {
         // A downcast is required for interfaces, see Bugzilla 3706

test/compilable/ice13920.d

@@ -0,0 +1,25 @@
+// REQUIRED_ARGS: -o-
+// PERMUTE_ARGS:
+
+class Foo
+{
+    void foo()
+    {
+        foreach (f; __traits(getOverloads, typeof(this), "bar"))
+        {
+            auto dg = &f;
+        }
+
+        foreach (f; __traits(getVirtualMethods, typeof(this), "bar"))
+        {
+            auto dg = &f;
+        }
+
+        foreach (f; __traits(getVirtualFunctions, typeof(this), "bar"))
+        {
+            auto dg = &f;
+        }
+    }
+
+    uint bar() { return 0; }
+}