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-rw-r--r--misc/insremque.c22
1 files changed, 15 insertions, 7 deletions
diff --git a/misc/insremque.c b/misc/insremque.c
index e366ac8..7f086cd 100644
--- a/misc/insremque.c
+++ b/misc/insremque.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1992, 1995, 1996 Free Software Foundation, Inc.
+/* Copyright (C) 1992, 1995, 1996, 2006 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@@ -24,12 +24,20 @@
void
insque (void *elem, void *prev)
{
- struct qelem *next = ((struct qelem *) prev)->q_forw;
- ((struct qelem *) prev)->q_forw = (struct qelem *) elem;
- if (next != NULL)
- next->q_back = (struct qelem *) elem;
- ((struct qelem *) elem)->q_forw = next;
- ((struct qelem *) elem)->q_back = (struct qelem *) prev;
+ if (prev == NULL)
+ {
+ ((struct qelem *) elem)->q_forw = NULL;
+ ((struct qelem *) elem)->q_back = NULL;
+ }
+ else
+ {
+ struct qelem *next = ((struct qelem *) prev)->q_forw;
+ ((struct qelem *) prev)->q_forw = (struct qelem *) elem;
+ if (next != NULL)
+ next->q_back = (struct qelem *) elem;
+ ((struct qelem *) elem)->q_forw = next;
+ ((struct qelem *) elem)->q_back = (struct qelem *) prev;
+ }
}
/* Unlink ELEM from the doubly-linked list that it is in. */