X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=unix%2Fuxsel.c;h=ef25cdb574e2a6cf7fe4bb95112be1e05e52b947;hb=095072fa46b2d7b8beafaddb2f873d2f500a1e10;hp=fa48507fced4a0590fa557a192d411c9c6888fca;hpb=b5423b51d468b76eb2b6cd19bb2c900b882e24f3;p=PuTTY.git

diff --git a/unix/uxsel.c b/unix/uxsel.c
index fa48507f..ef25cdb5 100644
--- a/unix/uxsel.c
+++ b/unix/uxsel.c
@@ -64,6 +64,8 @@ void uxsel_set(int fd, int rwx, uxsel_callback_fn callback)
 {
     struct fd *newfd;
 
+    assert(fd >= 0);
+
     uxsel_del(fd);
 
     if (rwx) {