From be2fe943c049d479bec9c476e196037678e05b32 Mon Sep 17 00:00:00 2001
From: Jacob1 <jfu614@gmail.com>
Date: Wed, 23 May 2012 20:08:53 -0400
Subject: [PATCH] Prevent accidental infinite loops in lua Also fix glitch when
 step_functions[0] is unregistered but others aren't

---
 .gitignore            |  2 +-
 includes/defines.h    |  1 +
 includes/luaconsole.h |  1 +
 src/interface.c       |  1 +
 src/luaconsole.c      | 35 +++++++++++++++++++++++++----------
 5 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/.gitignore b/.gitignore
index f22dc53ce..27e78a6ec 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,4 +17,4 @@ src/python/stdlib/*
 *.bat
 *.o
 *.me
-*
\ No newline at end of file
+*
diff --git a/includes/defines.h b/includes/defines.h
index 28cdbd2b6..bb57b8e39 100644
--- a/includes/defines.h
+++ b/includes/defines.h
@@ -189,6 +189,7 @@ extern int ngrav_enable;
 int limitFPS;
 int water_equal_test;
 extern int quickoptions_tooltip_fade;
+extern int loop_time;
 
 extern int debug_flags;
 #define DEBUG_PERF_FRAMECOUNT 256
diff --git a/includes/luaconsole.h b/includes/luaconsole.h
index 83fa4054a..ce8f6b1c6 100644
--- a/includes/luaconsole.h
+++ b/includes/luaconsole.h
@@ -62,6 +62,7 @@ int luacon_particle_getproperty(char * key, int * format);
 int luacon_transition_getproperty(char * key, int * format);
 int luacon_element_getproperty(char * key, int * format, unsigned int * modified_stuff);
 int process_command_lua(pixel *vid_buf, char *console, char *console_error);
+void lua_hook(lua_State *L, lua_Debug *ar);
 
 int getPartIndex_curIdx;
 
diff --git a/src/interface.c b/src/interface.c
index 9e8c6db86..f2f4b180a 100644
--- a/src/interface.c
+++ b/src/interface.c
@@ -2683,6 +2683,7 @@ int sdl_poll(void)
 {
 	SDL_Event event;
 	sdl_key=sdl_rkey=sdl_wheel=sdl_ascii=0;
+	loop_time = SDL_GetTicks();
 	while (SDL_PollEvent(&event))
 	{
 		switch (event.type)
diff --git a/src/luaconsole.c b/src/luaconsole.c
index 759dd7522..92b58bb78 100644
--- a/src/luaconsole.c
+++ b/src/luaconsole.c
@@ -32,6 +32,7 @@ int tptProperties; //Table for some TPT properties
 int tptPropertiesVersion;
 int tptElements; //Table for TPT element names
 int tptParts, tptPartsMeta, tptElementTransitions, tptPartsCData, tptPartMeta, tptPart, cIndex;
+int loop_time = 0;
 void luacon_open(){
 	int i = 0, j;
 	char tmpname[12];
@@ -219,6 +220,7 @@ tpt.partsdata = nil");
 	{
 		lua_el_mode[i] = 0;
 	}
+	lua_sethook(l, &lua_hook, LUA_MASKCOUNT, 200);
 }
 #ifndef FFI
 int luacon_partread(lua_State* l){
@@ -733,26 +735,39 @@ int luacon_step(int mx, int my, int selectl, int selectr){
 	lua_setfield(l, tptProperties, "mousey");
 	lua_setfield(l, tptProperties, "selectedl");
 	lua_setfield(l, tptProperties, "selectedr");
-	if(step_functions[0]){
-		//Set mouse globals
-		for(i = 0; i<6; i++){
-			if(step_functions[i]){
-				lua_rawgeti(l, LUA_REGISTRYINDEX, step_functions[i]);
-				callret = lua_pcall(l, 0, 0, 0);
-				if (callret)
+	for(i = 0; i<6; i++){
+		if(step_functions[i]){
+			loop_time = SDL_GetTicks();
+			lua_rawgeti(l, LUA_REGISTRYINDEX, step_functions[i]);
+			callret = lua_pcall(l, 0, 0, 0);
+			if (callret)
+			{
+				// failed, TODO: better error reporting
+				printf("%s\n",luacon_geterror());
+				if (!strcmp(luacon_geterror(),"Error: Infinite loop"))
 				{
-					// failed, TODO: better error reporting
-					printf("%s\n",luacon_geterror());
+					lua_pushcfunction(l,&luatpt_unregister_step);
+					lua_rawgeti(l, LUA_REGISTRYINDEX, step_functions[i]);
+					lua_pcall(l, 1, 0, 0);
 				}
 			}
 		}
-		return tempret;
 	}
 	return 0;
 }
 int luacon_eval(char *command){
+	loop_time = SDL_GetTicks();
 	return luaL_dostring (l, command);
 }
+void lua_hook(lua_State *L, lua_Debug *ar)
+{
+	if(ar->event == LUA_HOOKCOUNT && SDL_GetTicks()-loop_time > 3000)
+	{
+		if (confirm_ui(vid_buf,"Infinite Loop","The Lua code might have an infinite loop. Press OK to stop it","OK"))
+			luaL_error(l,"Error: Infinite loop");
+		loop_time = SDL_GetTicks();
+	}
+}
 int luacon_part_update(int t, int i, int x, int y, int surround_space, int nt)
 {
 	int retval = 0;