Fix Issue 23912 - Destructor disables scope inference

compiler/src/dmd/expression.d

@@ -699,6 +699,20 @@ VarDeclaration expToVariable(Expression e)
             case EXP.super_:
                 return (cast(ThisExp)e).var.isVarDeclaration();
 
+            // Temporaries for rvalues that need destruction
+            // are of form: (T s = rvalue, s). For these cases
+            // we can just return var declaration of `s`. However,
+            // this is intentionally not calling `Expression.extractLast`
+            // because at this point we cannot infer the var declaration
+            // of more complex generated comma expressions such as the
+            // one for the array append hook.
+            case EXP.comma:
+            {
+                if (auto ve = e.isCommaExp().e2.isVarExp())
+                    return ve.var.isVarDeclaration();
+
+                return null;
+            }
             default:
                 return null;
         }

compiler/test/compilable/test23912.d

@@ -0,0 +1,17 @@
+// https://issues.dlang.org/show_bug.cgi?id=23912
+// REQUIRED_ARGS: -preview=dip1000
+
+struct Test
+{
+    string val;
+
+    this(return scope string val) scope @safe {}
+    ~this() scope @safe {}
+}
+
+void giver(scope string input) @safe
+{
+    accepts(Test(input));
+}
+
+void accepts(scope Test test) @safe {}