From 7e3495747035d13f72ba869195b21f4e61ee283a Mon Sep 17 00:00:00 2001 From: camthesaxman Date: Sun, 14 Jan 2018 16:29:27 -0600 Subject: add comment about NULL pointer dereference --- src/field/fieldmap.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) (limited to 'src/field/fieldmap.c') diff --git a/src/field/fieldmap.c b/src/field/fieldmap.c index 7a31ae720..7383bb174 100644 --- a/src/field/fieldmap.c +++ b/src/field/fieldmap.c @@ -86,18 +86,20 @@ void map_copy_with_padding(u16 *map, u16 width, u16 height) void sub_80560AC(struct MapHeader *mapHeader) { + // BUG: This results in a null pointer dereference when mapHeader->connections + // is NULL, causing count to be assigned a garbage value. This garbage value + // just so happens to have the most significant bit set, so it is treated as + // negative and the loop below thankfully never executes in this scenario. + int count = mapHeader->connections->count; + struct MapConnection *connection = mapHeader->connections->connections; int i; - struct MapConnection *connection; - struct MapHeader *cMap; - u32 offset; - int count; - count = mapHeader->connections->count; - connection = mapHeader->connections->connections; + gUnknown_0202E850 = sDummyConnectionFlags; for (i = 0; i < count; i++, connection++) { - cMap = mapconnection_get_mapheader(connection); - offset = connection->offset; + struct MapHeader *cMap = mapconnection_get_mapheader(connection); + u32 offset = connection->offset; + switch (connection->direction) { case CONNECTION_SOUTH: -- cgit v1.2.3