diff -r 3c48b2b3cb83 -r 6ef84b000bd6 src/base/random.cc
--- a/src/base/random.cc	Fri Aug 13 06:16:30 2010 -0700
+++ b/src/base/random.cc	Fri Aug 13 11:37:53 2010 -0500
@@ -65,7 +65,9 @@
 uint32_t
 Random::genrand(uint32_t max)
 {
-    int log = ceilLog2(max);
+    if (max == 0)
+        return 0;
+    int log = (max == 1) ? 1 : ceilLog2(max);
     int shift = (sizeof(uint32_t) * 8 - log);
     uint32_t random;
 
@@ -79,7 +81,9 @@
 uint64_t
 Random::genrand(uint64_t max)
 {
-    int log = ceilLog2(max);
+    if (max == 0)
+        return 0;
+    int log = (max == 1) ? 1 : ceilLog2(max);
     int shift = (sizeof(uint64_t) * 8 - log);
     uint64_t random;