empire/empserver
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Fix bitmap overruns when WORLD_X * WORLD_Y not a multiple of 16

Browse source 
World-sized bitmaps were allocated with size WORLD_SZ() / 8, which
expands to (WORLD_X * WORLD_Y / 2) / 8.  The divisions truncate unless
WORLD_X * WORLD_Y is a multiple of 16.  The bitmaps were one byte too
small then.  Bitmap overruns happen when:

* A lookout looks at one of the last sectors of the sector file.
  Besides commands look and llook, this affects navigate and march
  sub-command 'l'.

* Command spy spies into one of the last sectors of the sector file.

* A map or nmap (but not a bmap) shows one of the last sectors of the
  sector file, or a sector that can see one of the last sectors
  (visual range is two sectors at 100% efficiency).  Besides commands
  lmap, map, nmap, pmap, smap, this affects move and transport
  sub-command 'm'.

Diagnosed with valgrind.

Already broken in BSD Empire 1.1 (bitmaps were on the stack then).
This commit is contained in:
Markus Armbruster 2011-02-28 06:58:51 +01:00
parent 6c9363cc4f
commit 88983a1a2e
3 changed files with 7 additions and 7 deletions
Download patch file Download diff file Expand all files Collapse all files

2
src/lib/commands/look.c
View file

@ -70,7 +70,7 @@ do_look(int type)
if (!snxtitem(&ni, type, player->argp[1], NULL))
return RET_SYN;
bitmap = calloc(WORLD_SZ() / 8, 1);
bitmap = calloc((WORLD_SZ() + 7) / 8, 1);
if (!bitmap) {
logerror("malloc failed in do_look\n");
pr("Memory error. Tell the deity.\n");