[lwp] Beware unsigned wrap-around.

We need to restart to avoid n_ips < 2*len.

1 files changed, 5 insertions, 2 deletions

diff --git a/src/lwp.c b/src/lwp.c
index d794abe..3986595 100644
--- a/src/lwp.c
+++ b/src/lwp.c
@@ -663,17 +663,20 @@ _lwp_prune_recursion (gpointer *ips, guint n_ips)
 {
     guint n, len;
 
+restart:
     for (len = 1; len < n_ips/2; len++) {
 	for (n = 0; n < n_ips - 2*len; n++) {
 	    guint m = n + len;
 	    while (memcmp (ips + n, ips + m, len * sizeof (gpointer)) == 0) {
-		m += len;
 		if (m + len >= n_ips)
 		    break;
+		m += len;
 	    }
 	    if (m != n + len) {
-		memmove (ips + n + len, ips + m, sizeof (gpointer) * (n_ips - m));
+		memmove (ips + n + len, ips + m,
+			 sizeof (gpointer) * (n_ips - m));
 		n_ips -= m - n - len;
+		goto restart;
 	    }
 	}
     }