(svn r17417) [0.7] -Backport from trunk:

- Fix: Incomplete check on validity of industry type when building industries (r17413)
- Fix: [Squirrel] Guard against Squirrel stack overflows (r17403)
- Fix: [NoAI] During every save a few slots on the Squirrel stack were leaked (r17402)
- Fix: [NoAI] Several AITile::* functions did not check whether their parameters were valid (r17378)

src/3rdparty/squirrel/squirrel/squtils.h

@@ -88,7 +88,7 @@ public:
 	}
 	SQUnsignedInteger capacity() { return _allocated; }
 	inline T &back() const { return _vals[_size - 1]; }
-	inline T& operator[](SQUnsignedInteger pos) const{ return _vals[pos]; }
+	inline T& operator[](SQUnsignedInteger pos) const{ assert(pos < _allocated); return _vals[pos]; }
 	T* _vals;
 private:
 	void _realloc(SQUnsignedInteger newsize)

src/3rdparty/squirrel/squirrel/sqvm.cpp

@@ -1503,7 +1503,19 @@ void SQVM::Pop(SQInteger n) {
 	}
 }
 
-void SQVM::Push(const SQObjectPtr &o) { _stack[_top++] = o; }
+void SQVM::Push(const SQObjectPtr &o) {
+	/* Normally the stack shouldn't get this full, sometimes it might. As of now
+	 * all cases have been bugs in "our" (OpenTTD) code. Trigger an assert for
+	 * all debug builds and for the release builds just increase the stack size.
+	 * This way getting a false positive isn't that bad (releases work fine) and
+	 * if there is something fishy it can be caught in RCs/nightlies. */
+#ifdef NDEBUG
+	if (_top >= (int)_stack.capacity()) _stack.resize(2 * _stack.capacity());
+#else
+	assert(_top < (int)_stack.capacity());
+#endif
+	_stack[_top++] = o;
+}
 SQObjectPtr &SQVM::Top() { return _stack[_top-1]; }
 SQObjectPtr &SQVM::PopGet() { return _stack[--_top]; }
 SQObjectPtr &SQVM::GetUp(SQInteger n) { return _stack[_top+n]; }

src/ai/api/ai_tile.cpp

@@ -87,31 +87,43 @@
 
 /* static */ bool AITile::HasTreeOnTile(TileIndex tile)
 {
+	if (!::IsValidTile(tile)) return false;
+
 	return ::IsTileType(tile, MP_TREES);
 }
 
 /* static */ bool AITile::IsFarmTile(TileIndex tile)
 {
+	if (!::IsValidTile(tile)) return false;
+
 	return (::IsTileType(tile, MP_CLEAR) && ::IsClearGround(tile, CLEAR_FIELDS));
 }
 
 /* static */ bool AITile::IsRockTile(TileIndex tile)
 {
+	if (!::IsValidTile(tile)) return false;
+
 	return (::IsTileType(tile, MP_CLEAR) && ::IsClearGround(tile, CLEAR_ROCKS));
 }
 
 /* static */ bool AITile::IsRoughTile(TileIndex tile)
 {
+	if (!::IsValidTile(tile)) return false;
+
 	return (::IsTileType(tile, MP_CLEAR) && ::IsClearGround(tile, CLEAR_ROUGH));
 }
 
 /* static */ bool AITile::IsSnowTile(TileIndex tile)
 {
+	if (!::IsValidTile(tile)) return false;
+
 	return (::IsTileType(tile, MP_CLEAR) && ::IsClearGround(tile, CLEAR_SNOW));
 }
 
 /* static */ bool AITile::IsDesertTile(TileIndex tile)
 {
+	if (!::IsValidTile(tile)) return false;
+
 	return (::IsTileType(tile, MP_CLEAR) && ::IsClearGround(tile, CLEAR_DESERT));
 }
 

src/industry_cmd.cpp

@@ -1642,7 +1642,10 @@ static Industry *CreateNewIndustryHelper(TileIndex tile, IndustryType type, DoCo
  */
 CommandCost CmdBuildIndustry(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
 {
-	const IndustrySpec *indspec = GetIndustrySpec(GB(p1, 0, 16));
+	IndustryType it = GB(p1, 0, 16);
+	if (it >= NUM_INDUSTRYTYPES) return CMD_ERROR;
+
+	const IndustrySpec *indspec = GetIndustrySpec(it);
 	const Industry *ind = NULL;
 
 	/* Check if the to-be built/founded industry is available for this climate. */
@@ -1681,7 +1684,8 @@ CommandCost CmdBuildIndustry(TileIndex tile, DoCommandFlag flags, uint32 p1, uin
 	} else {
 		int count = indspec->num_table;
 		const IndustryTileTable * const *itt = indspec->table;
-		int num = Clamp(GB(p1, 16, 16), 0, count - 1);
+		int num = GB(p1, 16, 16);
+		if (num >= count) return CMD_ERROR;
 
 		_error_message = STR_0239_SITE_UNSUITABLE;
 		do {

src/script/squirrel.cpp

@@ -222,7 +222,7 @@ bool Squirrel::CallMethod(HSQOBJECT instance, const char *method_name, HSQOBJECT
 	if (ret != NULL) sq_getstackobj(vm, -1, ret);
 	/* Reset the top, but don't do so for the AI main function, as we need
 	 *  a correct stack when resuming. */
-	if (!this->IsSuspended()) sq_settop(this->vm, top);
+	if (suspend == -1) sq_settop(this->vm, top);
 	/* Restore the return-value location. */
 	this->vm->_suspended_target = last_target;