unanswered pull frees the slot

When the answer to a pull is overdue (the sync reply timeout: 1 s in the
simtests, 10 s in production), the pull gives up the slot, and the next
waiting neighbour is pulled at once.

1 files changed, 4 insertions, 3 deletions

diff --git a/docs/peers.md b/docs/peers.md
index a521db3..be04b16 100644
--- a/docs/peers.md
+++ b/docs/peers.md
@@ -289,9 +289,10 @@ own announcement or STATUS brought them, are this node's: announcements wait 200
 the other skips it), and a neighbour that lacks those heads pulls them (it sets them as the peer's heads in its sync state, so Automerge asks
 for what's missing), if it still lacks them after a round trip to the announcer (at
 most 1 s): while writes go on, the newest are usually on their way to it along a
-writer's tree, and would otherwise come twice. It pulls from one neighbour at a time (15 s timeout); neighbours
-that announce heads it lacks meanwhile wait their turn and are pulled from as soon as
-the current pull is answered, if they still have something it lacks. The regular
+writer's tree, and would otherwise come twice. It pulls from one neighbour at a time
+(until the answer is overdue, by the sync reply timeout, or 15 s); neighbours that
+announce heads it lacks meanwhile wait their turn and are pulled from as soon as the
+current pull is answered or overdue, if they still have something it lacks. The regular
 STATUS (every third keepalive) triggers the same pull, so gaps close within a few
 keepalive intervals. Changes that pass on along a writer's tree (below) go at once,
 without announcement or pull; the announcements catch what the trees miss. A node