Fix TNT floodfill crash

src/simulation/CoordStack.h

@@ -0,0 +1,74 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef Simulation_CoordStack_h
+#define Simulation_CoordStack_h
+
+#include "Config.h" // for XRES and YRES
+#include <exception>
+
+class CoordStackOverflowException: public std::exception
+{
+public:
+	CoordStackOverflowException() { }
+	virtual const char* what() const throw()
+	{
+		return "Maximum number of entries in the coordinate stack was exceeded";
+	}
+	~CoordStackOverflowException() throw() {};
+};
+
+class CoordStack
+{
+private:
+	unsigned short (*stack)[2];
+	int stack_size;
+	const static int stack_limit = XRES*YRES;
+public:
+	CoordStack() :
+		stack(NULL),
+		stack_size(0)
+	{
+		stack = (unsigned short(*)[2])(malloc(sizeof(unsigned short)*2*stack_limit));
+	}
+	~CoordStack()
+	{
+		if (stack) free(stack);
+	}
+	void push(int x, int y)
+	{
+		if (stack_size>=stack_limit)
+			throw CoordStackOverflowException();
+		stack[stack_size][0] = x;
+		stack[stack_size][1] = y;
+		stack_size++;
+	}
+	void pop(int& x, int& y)
+	{
+		stack_size--;
+		x = stack[stack_size][0];
+		y = stack[stack_size][1];
+	}
+	int getSize() const
+	{
+		return stack_size;
+	}
+	void clear()
+	{
+		stack_size = 0;
+	}
+};
+
+#endif 

src/simulation/Simulation.cpp

@@ -13,6 +13,7 @@
 #include "Air.h"
 #include "Gravity.h"
 #include "elements/Element.h"
+#include "CoordStack.h"
 
 //#include "graphics/Renderer.h"
 //#include "graphics/Graphics.h"
@@ -379,24 +380,38 @@ bool Simulation::FloodFillPmapCheck(int x, int y, int type)
 		return (pmap[y][x]&0xFF) == type;
 }
 
-int Simulation::flood_prop_2(int x, int y, size_t propoffset, PropertyValue propvalue, StructProperty::PropertyType proptype, int parttype, char * bitmap)
+int Simulation::flood_prop(int x, int y, size_t propoffset, PropertyValue propvalue, StructProperty::PropertyType proptype)
 {
-	int x1, x2, i, dy = 1;
+	int i, x1, x2, dy = 1;
+	int did_something = 0;
+	int r = pmap[y][x];
+	if (!r)
+		r = photons[y][x];
+	if (!r)
+		return 0;
+	int parttype = (r&0xFF);
+	char * bitmap = (char*)malloc(XRES*YRES); //Bitmap for checking
+	if (!bitmap) return -1;
+	memset(bitmap, 0, XRES*YRES);
+	try
+	{
+		CoordStack cs;
+		cs.push(x, y);
+		do
+		{
+			cs.pop(x, y);
+			x1 = x2 = x;
 			x1 = x2 = x;
 			while (x1>=CELL)
 			{
 				if (!FloodFillPmapCheck(x1-1, y, parttype) || bitmap[(y*XRES)+x1-1])
-		{
 					break;
-		}
 				x1--;
 			}
 			while (x2<XRES-CELL)
 			{
 				if (!FloodFillPmapCheck(x2+1, y, parttype) || bitmap[(y*XRES)+x2+1])
-		{
 					break;
-		}
 				x2++;
 			}
 			for (x=x1; x<=x2; x++)
@@ -424,33 +439,26 @@ int Simulation::flood_prop_2(int x, int y, size_t propoffset, PropertyValue prop
 						break;
 				}
 				bitmap[(y*XRES)+x] = 1;
+				did_something = 1;
 			}
 			if (y>=CELL+dy)
 				for (x=x1; x<=x2; x++)
 					if (FloodFillPmapCheck(x, y-dy, parttype) && !bitmap[((y-dy)*XRES)+x])
-				if (!flood_prop_2(x, y-dy, propoffset, propvalue, proptype, parttype, bitmap))
-					return 0;
+						cs.push(x, y-dy);
 			if (y<YRES-CELL-dy)
 				for (x=x1; x<=x2; x++)
 					if (FloodFillPmapCheck(x, y+dy, parttype) && !bitmap[((y+dy)*XRES)+x])
-				if (!flood_prop_2(x, y+dy, propoffset, propvalue, proptype, parttype, bitmap))
-					return 0;
-	return 1;
+						cs.push(x, y+dy);
+		} while (cs.getSize()>0);
 	}
-
-int Simulation::flood_prop(int x, int y, size_t propoffset, PropertyValue propvalue, StructProperty::PropertyType proptype)
+	catch (std::exception& e)
 	{
-	int r = 0;
-	char * bitmap = (char *)malloc(XRES*YRES); //Bitmap for checking
-	memset(bitmap, 0, XRES*YRES);
-	r = pmap[y][x];
-	if (!r)
-		r = photons[y][x];
-	if (!r)
-		return 1;
-	flood_prop_2(x, y, propoffset, propvalue, proptype, r&0xFF, bitmap);
+		std::cerr << e.what() << std::endl;
 		free(bitmap);
-	return 0;
+		return -1;
+	}
+	free(bitmap);
+	return did_something;
 }
 
 SimulationSample Simulation::GetSample(int x, int y)

src/simulation/Simulation.h

@@ -135,7 +135,6 @@ public:
 	void kill_part(int i);
 	bool FloodFillPmapCheck(int x, int y, int type);
 	int flood_prop(int x, int y, size_t propoffset, PropertyValue propvalue, StructProperty::PropertyType proptype);
-	int flood_prop_2(int x, int y, size_t propoffset, PropertyValue propvalue, StructProperty::PropertyType proptype, int parttype, char * bitmap);
 	int flood_water(int x, int y, int i, int originaly, int check);
 	int FloodINST(int x, int y, int fullc, int cm);
 	void detach(int i);