[Scummvm-git-logs] scummvm master -> de1338787f65ac0b7a225b8149eebe8d27005fc3

[antoniou79]

This automated email contains information about 1 new commit which have been
pushed to the 'scummvm' repo located at https://github.com/scummvm/scummvm .

Summary:
de1338787f COMMON: Fix divide by zero in getRandomNumber()


Commit: de1338787f65ac0b7a225b8149eebe8d27005fc3
    https://github.com/scummvm/scummvm/commit/de1338787f65ac0b7a225b8149eebe8d27005fc3
Author: Aapo Vienamo (aapo.vienamo at iki.fi)
Date: 2021-08-02T13:40:11+03:00

Commit Message:
COMMON: Fix divide by zero in getRandomNumber()

Calling RandomSource::getRandomNumber() results in divide by zero
exception when called with max = 4294967295 as max + 1 overflows to zero
and the subsequent modulus operation causes the exception.

Certain game saves in Bladerunner trigger this.

Changed paths:
    common/random.cpp


diff --git a/common/random.cpp b/common/random.cpp
index d39f9a4255..ed3bc4dbb8 100644
--- a/common/random.cpp
+++ b/common/random.cpp
@@ -20,6 +20,8 @@
  *
  */
 
+#include <climits>
+
 #include "common/random.h"
 #include "common/system.h"
 #include "gui/EventRecorder.h"
@@ -46,6 +48,9 @@ void RandomSource::setSeed(uint32 seed) {
 uint RandomSource::getRandomNumber(uint max) {
 	_randSeed = 0xDEADBF03 * (_randSeed + 1);
 	_randSeed = (_randSeed >> 13) | (_randSeed << 19);
+
+	if (max == UINT_MAX)
+		return _randSeed;
 	return _randSeed % (max + 1);
 }