Add a method for copying part of an XML tree into another tree and use it to fix Cocoa debugger fatal error

src/lib/util/xmlfile.cpp

@@ -70,7 +70,7 @@ file::~file() { }
 
 file::ptr file::create()
 {
-	try { return ptr(new file()); }
+	try { return ptr(new file); }
 	catch (...) { return ptr(); }
 }
 
@@ -213,7 +213,12 @@ data_node::data_node(data_node *parent, const char *name, const char *value)
 
 data_node::~data_node()
 {
-	/* free the children */
+	free_children();
+}
+
+
+void data_node::free_children()
+{
 	for (data_node *nchild = nullptr; m_first_child; m_first_child = nchild)
 	{
 		/* note the next node and free this node */
@@ -382,6 +387,43 @@ data_node *data_node::get_or_add_child(const char *name, const char *value)
 }
 
 
+// recursively copy as child of another node
+data_node *data_node::copy_into(data_node &parent) const
+{
+	data_node *const result = parent.add_child(get_name(), get_value());
+	result->m_attributes = m_attributes;
+
+	data_node *dst = result;
+	data_node const *src = get_first_child();
+	while (src && (&parent != dst))
+	{
+		dst = dst->add_child(src->get_name(), src->get_value());
+		dst->m_attributes = src->m_attributes;
+		data_node const *next = src->get_first_child();
+		if (next)
+		{
+			src = next;
+		}
+		else
+		{
+			dst = dst->get_parent();
+			next = src->get_next_sibling();
+			if (next)
+			{
+				src = next;
+			}
+			else
+			{
+				dst = dst->get_parent();
+				src = src->get_parent()->get_next_sibling();
+			}
+		}
+	}
+
+	return result;
+}
+
+
 /*-------------------------------------------------
     delete_node - delete a node and its
     children
@@ -389,9 +431,10 @@ data_node *data_node::get_or_add_child(const char *name, const char *value)
 
 void data_node::delete_node()
 {
-	/* first unhook us from the list of children of our parent */
+	/* don't allow deletion of document root */
 	if (m_parent)
 	{
+		/* first unhook us from the list of children of our parent */
 		for (data_node **pnode = &m_parent->m_first_child; *pnode; pnode = &(*pnode)->m_next)
 		{
 			if (*pnode == this)
@@ -400,10 +443,15 @@ void data_node::delete_node()
 				break;
 			}
 		}
-	}
 
-	/* now free ourselves and our children */
-	delete this;
+		/* now free ourselves and our children */
+		delete this;
+	}
+	else
+	{
+		/* remove all children of document root */
+		free_children();
+	}
 }
 
 

src/lib/util/xmlfile.h

@@ -118,6 +118,9 @@ public:
 	// either return an existing child node or create one if it doesn't exist
 	data_node *get_or_add_child(const char *name, const char *value);
 
+	// recursively copy as child of another node
+	data_node *copy_into(data_node &parent) const;
+
 	// delete a node and its children
 	void delete_node();
 
@@ -189,6 +192,8 @@ private:
 	attribute_node *get_attribute(const char *attribute);
 	attribute_node const *get_attribute(const char *attribute) const;
 
+	void free_children();
+
 
 	data_node *                 m_next;
 	data_node *                 m_first_child;
@@ -208,7 +213,7 @@ public:
 
 	~file();
 
-	// create a new empty xml file object
+	// create a new, empty XML file
 	static ptr create();
 
 	// parse an XML file into its nodes

src/osd/modules/debugger/debugosx.mm

@@ -30,6 +30,8 @@
 #import "osx/debugconsole.h"
 #import "osx/debugwindowhandler.h"
 
+#include "util/xmlfile.h"
+
 #include <atomic>
 
 
@@ -44,7 +46,8 @@ public:
 		osd_module(OSD_DEBUG_PROVIDER, "osx"),
 		debug_module(),
 		m_machine(nullptr),
-		m_console(nil)
+		m_console(nil),
+		m_config()
 	{
 	}
 
@@ -69,6 +72,7 @@ private:
 
 	running_machine *m_machine;
 	MAMEDebugConsole *m_console;
+	util::xml::file::ptr m_config;
 
 	static std::atomic_bool s_added_menus;
 };
@@ -141,6 +145,11 @@ void debugger_osx::wait_for_debugger(device_t &device, bool firststop)
 	// make sure the debug windows are visible
 	if (firststop)
 	{
+		if (m_config)
+		{
+			[m_console loadConfiguration:m_config->get_first_child()];
+			m_config.reset();
+		}
 		NSDictionary *info = [NSDictionary dictionaryWithObjectsAndKeys:[NSValue valueWithPointer:&device],
 																		@"MAMEDebugDevice",
 																		[NSValue valueWithPointer:m_machine],
@@ -296,10 +305,17 @@ void debugger_osx::config_load(config_type cfgtype, util::xml::data_node const *
 {
 	if ((config_type::GAME == cfgtype) && parentnode)
 	{
-		NSAutoreleasePool *const pool = [[NSAutoreleasePool alloc] init];
-		create_console();
-		[m_console loadConfiguration:parentnode];
-		[pool release];
+		if (m_console)
+		{
+			NSAutoreleasePool *const pool = [[NSAutoreleasePool alloc] init];
+			[m_console loadConfiguration:parentnode];
+			[pool release];
+		}
+		else
+		{
+			m_config = util::xml::file::create();
+			parentnode->copy_into(*m_config);
+		}
 	}
 }