MOHAWK: Fix changing the stack via an opcode

svn-id: r54676

2 files changed, 9 insertions, 1 deletions

diff --git a/engines/mohawk/myst.cpp b/engines/mohawk/myst.cpp
index 6cab8f8eec..f141a5aa68 100644
--- a/engines/mohawk/myst.cpp
+++ b/engines/mohawk/myst.cpp
@@ -82,6 +82,8 @@ MohawkEngine_Myst::MohawkEngine_Myst(OSystem *syst, const MohawkGameDescription
 	_cursorHintCount = 0;
 	_cursorHints = NULL;
 
+	_prevStack = NULL;
+
 	_view.conditionalImageCount = 0;
 	_view.conditionalImages = NULL;
 	_view.soundList = NULL;
@@ -105,6 +107,7 @@ MohawkEngine_Myst::~MohawkEngine_Myst() {
 	delete _saveLoad;
 	delete _loadDialog;
 	delete _optionsDialog;
+	delete _prevStack;
 
 	delete[] _cursorHints;
 
@@ -365,7 +368,11 @@ void MohawkEngine_Myst::changeToStack(uint16 stack) {
 
 	_curStack = stack;
 
-	delete _scriptParser;
+	// Delete the previous stack and move the current stack to the previous one
+	// There's probably a better way to do this, but the script classes shouldn't
+	// take up much memory.
+	delete _prevStack;
+	_prevStack = _scriptParser;
 
 	switch (_curStack) {
 	case kSeleniticStack:
diff --git a/engines/mohawk/myst.h b/engines/mohawk/myst.h
index 0a2b0fbbbc..63b9c11ef4 100644
--- a/engines/mohawk/myst.h
+++ b/engines/mohawk/myst.h
@@ -196,6 +196,7 @@ private:
 	MystConsole *_console;
 	GUI::SaveLoadChooser *_loadDialog;
 	MystOptionsDialog *_optionsDialog;
+	MystScriptParser *_prevStack;
 	ResourceCache _cache;
 	void cachePreload(uint32 tag, uint16 id);