Avoid infinite loop if the file's length is negative.

Fixes bug 4664.

diff --git a/generator.c b/generator.c
index 01398b5..b12087f 100644 (file)
--- a/generator.c
+++ b/generator.c
@@ -567,6 +567,12 @@ static void sum_sizes_sqroot(struct sum_struct *sum, int64 len)
        int s2length;
        int64 l;
 
+       if (len < 0) {
+               /* The file length overflowed our int64 var, so we can't process this file. */
+               sum->count = -1; /* indicate overflow error */
+               return;
+       }
+
        if (block_size)
                blength = block_size;
        else if (len <= BLOCK_SIZE * BLOCK_SIZE)