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Fix core RNG collapsing to ~0-1 on Linux due to integer overflow

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CWorldServer::RandNumber (and three inlined copies of the same pattern
in worldpackets.cpp's item-refine code) computed "range*rand()" in
integer arithmetic before dividing by (RAND_MAX + 1.0). On Windows
RAND_MAX is 32767 (15-bit), so this never overflowed. On Linux/glibc
RAND_MAX is 2147483647 (2^31-1), so "range*rand()" overflows a 32-bit
UINT for the vast majority of rand() outputs, wrapping to a small
value -- the division by ~2^31 then collapses the result to ~0 or 1
almost always, regardless of the requested range. This made every
percentage-based roll in the game (item drop selection, refine
durability/stats, and anything else using RandNumber) behave as if
called with range 1-2 instead of the real range, which is why item
drops effectively never triggered post-port. Cast to double before
the multiply so it can't overflow.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
This commit is contained in:
ThomasandClaude Sonnet 5 committed 2026-07-09 07:24:14 +02:00
1 parent 560f6a968f
commit f053a06920
2 files changed
+11 -7
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Src/World Server/worldpackets.cpp
+3 -3
View File
@@ -3162,18 +3162,18 @@ bool CWorldServer::pakCraft( CPlayer* thisclient, CPacket* P )
int lowest = thisclient->Attr->Con/ 10 + 17;
int highest = thisclient->Attr->Con / 10 + 70;
int range = (highest - lowest) + 1;
item.durability = lowest+int(range*rand()/(RAND_MAX + 1.0));
item.durability = lowest+int((double)range*rand()/(RAND_MAX + 1.0));
// stats randomizer
int changeofstatslow = thisclient->Attr->Sen / 13 + 10;
int changeofstatshigh = thisclient->Attr->Sen / 13 + 50;
int changeofstatsrange = (changeofstatshigh-changeofstatslow)+1;
if (changeofstatslow+int(changeofstatsrange*rand()/(RAND_MAX + 1.0)) > 50)
if (changeofstatslow+int((double)changeofstatsrange*rand()/(RAND_MAX + 1.0)) > 50)
{
int statslowget = 1;
int statshighget = 256;
int setstatrange=(statshighget-statslowget)+1;
item.stats = statslowget + int(setstatrange*rand()/(RAND_MAX + 1.0));
item.stats = statslowget + int((double)setstatrange*rand()/(RAND_MAX + 1.0));
item.appraised = 1;
}
else