1 files changed, 30 insertions, 7 deletions

diff --git a/src/map/map.c b/src/map/map.c
index 4477d109c..24d571498 100644
--- a/src/map/map.c
+++ b/src/map/map.c
@@ -261,11 +261,13 @@ static int map_addblock(struct block_list *bl)
 	pos = x/BLOCK_SIZE+(y/BLOCK_SIZE)*map->list[m].bxs;
 
 	if (bl->type == BL_MOB) {
+		Assert_ret(map->list[m].block_mob != NULL);
 		bl->next = map->list[m].block_mob[pos];
 		bl->prev = &map->bl_head;
 		if (bl->next) bl->next->prev = bl;
 		map->list[m].block_mob[pos] = bl;
 	} else {
+		Assert_ret(map->list[m].block != NULL);
 		bl->next = map->list[m].block[pos];
 		bl->prev = &map->bl_head;
 		if (bl->next) bl->next->prev = bl;
@@ -307,8 +309,10 @@ static int map_delblock(struct block_list *bl)
 	if (bl->prev == &map->bl_head) {
 		//Since the head of the list, update the block_list map of []
 		if (bl->type == BL_MOB) {
+			Assert_ret(map->list[bl->m].block_mob != NULL);
 			map->list[bl->m].block_mob[pos] = bl->next;
 		} else {
+			Assert_ret(map->list[bl->m].block != NULL);
 			map->list[bl->m].block[pos] = bl->next;
 		}
 	} else {
@@ -450,6 +454,12 @@ static int map_count_oncell(int16 m, int16 x, int16 y, int type, int flag)
 	struct block_list *bl;
 	int count = 0;
 
+	Assert_ret(m >= -1);
+	if (m < 0)
+		return 0;
+	Assert_ret(m < map->count);
+	Assert_ret(map->list[m].block != NULL);
+
 	if (x < 0 || y < 0 || (x >= map->list[m].xs) || (y >= map->list[m].ys))
 		return 0;
 
@@ -512,6 +522,12 @@ static struct skill_unit *map_find_skill_unit_oncell(struct block_list *target,
 	nullpo_retr(NULL, target);
 	m = target->m;
 
+	Assert_ret(m >= -1);
+	if (m < 0)
+		return 0;
+	Assert_ret(m < map->count);
+	Assert_ret(map->list[m].block != NULL);
+
 	if (x < 0 || y < 0 || (x >= map->list[m].xs) || (y >= map->list[m].ys))
 		return NULL;
 
@@ -586,8 +602,11 @@ static int map_vforeachinmap(int (*func)(struct block_list*, va_list), int16 m,
 	struct block_list *bl;
 	int blockcount = map->bl_list_count;
 
+	Assert_ret(m >= -1);
 	if (m < 0)
 		return 0;
+	Assert_ret(m < map->count);
+	Assert_ret(map->list[m].block != NULL);
 
 	bsize = map->list[m].bxs * map->list[m].bys;
 	for (i = 0; i < bsize; i++) {
@@ -719,24 +738,28 @@ static int bl_getall_area(int type, int m, int x0, int y0, int x1, int y1, int (
 	struct block_list *bl;
 	int found = 0;
 
+	Assert_ret(m >= -1);
 	if (m < 0)
 		return 0;
+	Assert_ret(m < map->count);
+	const struct map_data *const listm = &map->list[m];
+	Assert_ret(listm->xs > 0 && listm->ys > 0);
+	Assert_ret(listm->block != NULL);
+
+	// Limit search area to map size
+	x0 = min(max(x0, 0), map->list[m].xs - 1);
+	y0 = min(max(y0, 0), map->list[m].ys - 1);
+	x1 = min(max(x1, 0), map->list[m].xs - 1);
+	y1 = min(max(y1, 0), map->list[m].ys - 1);
 
 	if (x1 < x0) swap(x0, x1);
 	if (y1 < y0) swap(y0, y1);
 
-	// Limit search area to map size
-	x0 = max(x0, 0);
-	y0 = max(y0, 0);
-	x1 = min(x1, map->list[m].xs - 1);
-	y1 = min(y1, map->list[m].ys - 1);
-
 	{
 		const int x0b = x0 / BLOCK_SIZE;
 		const int x1b = x1 / BLOCK_SIZE;
 		const int y0b = y0 / BLOCK_SIZE;
 		const int y1b = y1 / BLOCK_SIZE;
-		const struct map_data *const listm = &map->list[m];
 		const int bxs0 = listm->bxs;
 
 		// duplication for better performance