Make sure that we don't compute a block size larger than MAX_BLOCK_SIZE.

diff --git a/generator.c b/generator.c
index 2ffd03f..1c08e5e 100644 (file)
--- a/generator.c
+++ b/generator.c
@@ -146,17 +146,20 @@ static void sum_sizes_sqroot(struct sum_struct *sum, uint64 len)
        else {
                int32 c;
                uint64 l;
-               for (c = 1, l = len; l >>= 2; c <<= 1) {
-                   assert(c > 0);
+               int cnt;
+               for (c = 1, l = len, cnt = 0; l >>= 2; c <<= 1, cnt++) {}
+               if (cnt >= 31 || c >= MAX_BLOCK_SIZE)
+                       blength = MAX_BLOCK_SIZE;
+               else {
+                   blength = 0;
+                   do {
+                           blength |= c;
+                           if (len < (uint64)blength * blength)
+                                   blength &= ~c;
+                           c >>= 1;
+                   } while (c >= 8);   /* round to multiple of 8 */
+                   blength = MAX(blength, BLOCK_SIZE);
                }
-               blength = 0;
-               do {
-                       blength |= c;
-                       if (len < (uint64)blength * blength)
-                               blength &= ~c;
-                       c >>= 1;
-               } while (c >= 8);       /* round to multiple of 8 */
-               blength = MAX(blength, BLOCK_SIZE);
        }
 
        if (protocol_version < 27) {