SUPERNOVA: Fix crash when displaying strings larger than the screen

2 files changed, 20 insertions, 7 deletions

diff --git a/engines/supernova/supernova.cpp b/engines/supernova/supernova.cpp
index 291e18d964..5bc87872c5 100644
--- a/engines/supernova/supernova.cpp
+++ b/engines/supernova/supernova.cpp
@@ -967,16 +967,32 @@ ScreenBufferStack::ScreenBufferStack()
 	: _last(_buffer) {
 }
 
-void ScreenBufferStack::push(int x, int y, int width, int height, int pitch) {
+void ScreenBufferStack::push(int x, int y, int width, int height) {
 	if (_last == ARRAYEND(_buffer))
 		return;
 
+	Graphics::Surface* screenSurface = g_system->lockScreen();
+
+	if (x < 0) {
+		width += x;
+		x = 0;
+	}
+	if (x + width > screenSurface->w)
+		width = screenSurface->w - x;
+
+	if (y < 0) {
+		height += y;
+		y = 0;
+	}
+	if (y + height > screenSurface->h)
+		height = screenSurface->h - y;
+
 	_last->_pixels = new byte[width * height];
 	byte *pixels = _last->_pixels;
-	const byte *screen = static_cast<const byte *>(g_system->lockScreen()->getBasePtr(x, y));
+	const byte *screen = static_cast<const byte *>(screenSurface->getBasePtr(x, y));
 	for (int i = 0; i < height; ++i) {
 		Common::copy(screen, screen + width, pixels);
-		screen += pitch;
+		screen += screenSurface->pitch;
 		pixels += width;
 	}
 	g_system->unlockScreen();
@@ -985,7 +1001,6 @@ void ScreenBufferStack::push(int x, int y, int width, int height, int pitch) {
 	_last->_y = y;
 	_last->_width = width;
 	_last->_height = height;
-	_last->_pitch = pitch;
 
 	++_last;
 }
diff --git a/engines/supernova/supernova.h b/engines/supernova/supernova.h
index 16c98887b0..b3ab3f45bf 100644
--- a/engines/supernova/supernova.h
+++ b/engines/supernova/supernova.h
@@ -55,7 +55,6 @@ struct ScreenBuffer {
 		, _y(0)
 		, _width(0)
 		, _height(0)
-		, _pitch(0)
 		, _pixels(NULL)
 	{}
 
@@ -64,13 +63,12 @@ struct ScreenBuffer {
 	int _y;
 	int _width;
 	int _height;
-	int _pitch;
 };
 class ScreenBufferStack {
 public:
 	ScreenBufferStack();
 
-	void push(int x, int y, int width, int height, int pitch = 320);
+	void push(int x, int y, int width, int height);
 	void restore();
 
 private: