Clean up a (nearly impossible) null check. Add a comment.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@15536 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 4 insertions, 0 deletions

diff --git a/apps/buffering.c b/apps/buffering.c
index 655e5cfdaf..c59fc52b8a 100644
--- a/apps/buffering.c
+++ b/apps/buffering.c
@@ -1006,7 +1006,11 @@ static struct memory_handle *prep_bufdata(int handle_id, size_t *size,
         do
         {
             sleep(1);
+            /* it is not safe for a non-buffering thread to sleep while
+             * holding a handle */
             h = find_handle(handle_id);
+            if (!h)
+                return NULL;
             avail = RINGBUF_SUB(h->widx, h->ridx);
         }
         while (h->filerem > 0 && avail < *size);