Test of nested ownership destruction order

tests/oo.test

@@ -392,6 +392,52 @@ test oo-1.21 {basic test of OO functionality: default relations} -setup {
 } -cleanup {
     interp delete $fresh
 } -result {{} {::oo::Slot ::oo::class ::oo::object} {::oo::define::filter ::oo::define::mixin ::oo::define::superclass ::oo::define::variable ::oo::objdefine::filter ::oo::objdefine::mixin ::oo::objdefine::variable} {::oo::Slot ::oo::class} {} {} {} {} {} {} ::oo::object ::oo::object ::oo::class ::oo::class ::oo::class}
+test oo-1.22 {basic test of OO functionality: nested ownership destruction order} -setup {
+    oo::class create parent
+} -body {
+    oo::class create abc {
+	superclass parent
+	variable n
+	constructor {} {set n 0}
+	method make {i} {set n $i; [self class] create xyz}
+	destructor {lappend ::deathOrder $n}
+    }
+    apply {n {
+	set ::deathOrder {}
+	# Make some "nested" objects
+	set base [abc new]
+	for {set i 1; set obj $base} {$i < $n} {incr i} {
+	     set obj [$obj make $i]
+	}
+	# Kill them all in one go; should come apart in right order!
+	$base destroy
+	return $::deathOrder
+    }} 5
+} -cleanup {
+    parent destroy
+} -result {1 2 3 4 0}
+test oo-1.23 {basic test of OO functionality: deep nested ownership} -setup {
+    oo::class create parent
+} -constraints knownBug -body {
+    oo::class create abc {
+	superclass parent
+	method make {} {[self class] create xyz}
+	destructor {incr ::count}
+    }
+    apply {n {
+	set ::count 0
+	# Make a lot of "nested" objects
+	set base [abc new]
+	for {set i 1; set obj $base} {$i < $n} {incr i} {
+	     set obj [$obj make]
+	}
+	# Kill them all in one go; should not crash!
+	$base destroy
+	return [expr {$n - $::count}]
+    }} 10000
+} -cleanup {
+    parent destroy
+} -result 0
 
 test oo-2.1 {basic test of OO functionality: constructor} -setup {
     # This is a bit complex because it needs to run in a sub-interp as