If CM_LeafCluster() returned -1, don't use that as array index, fix #894

It seems to return -1 if the leaf is in the void; sometimes it
also seems to happen when you're just close to a wall, maybe due to
(mis)prediction.
ASan complains about this, but in practice it probably can't cause
issues, as the byte left to the mask array (from CM_ClusterPVS() or
CM_ClusterPHS()) will either belong to another global variable or
padding between them. Fixed it anyway.
This commit is contained in:
Daniel Gibson 2022-10-08 16:33:41 +02:00
parent d29e551773
commit 4d6bdcc853
2 changed files with 11 additions and 3 deletions

View file

@ -293,7 +293,10 @@ PF_inPVS(vec3_t p1, vec3_t p2)
cluster = CM_LeafCluster(leafnum);
area2 = CM_LeafArea(leafnum);
if (mask && (!(mask[cluster >> 3] & (1 << (cluster & 7)))))
// cluster -1 means "not in a visible leaf" or something like that (void?)
// so p1 and p2 probably don't "see" each other.
// either way, we must avoid using a negative index into mask[]!
if (cluster < 0 || (!(mask[cluster >> 3] & (1 << (cluster & 7)))))
{
return false;
}
@ -326,7 +329,10 @@ PF_inPHS(vec3_t p1, vec3_t p2)
cluster = CM_LeafCluster(leafnum);
area2 = CM_LeafArea(leafnum);
if (mask && (!(mask[cluster >> 3] & (1 << (cluster & 7)))))
// cluster -1 means "not in a visible leaf" or something like that (void?)
// so p1 and p2 probably don't "hear" each other.
// either way, we must avoid using a negative index into mask[]!
if (cluster < 0 || (!(mask[cluster >> 3] & (1 << (cluster & 7)))))
{
return false; /* more than one bounce away */
}

View file

@ -227,7 +227,9 @@ SV_Multicast(vec3_t origin, multicast_t to)
continue;
}
if (!(mask[cluster >> 3] & (1 << (cluster & 7))))
// cluster can be -1 if we're in the void (or sometime just at a wall)
// and using a negative index into mask[] would be invalid
if (cluster < 0 || !(mask[cluster >> 3] & (1 << (cluster & 7))))
{
continue;
}