reset pending push promises if user drops all refs (#199)

src/proto/streams/prioritize.rs

@@ -87,6 +87,7 @@ impl Prioritize {
     pub fn schedule_send(&mut self, stream: &mut store::Ptr, task: &mut Option<Task>) {
         // If the stream is waiting to be opened, nothing more to do.
         if !stream.is_pending_open {
+            trace!("schedule_send; {:?}", stream.id);
             // Queue the stream
             self.pending_send.push(stream);
 

src/proto/streams/recv.rs

@@ -615,6 +615,8 @@ impl Recv {
             return;
         }
 
+        trace!("enqueue_reset_expiration; {:?}", stream.id);
+
         if !counts.can_inc_num_reset_streams() {
             // try to evict 1 stream if possible
             // if max allow is 0, this won't be able to evict,

src/proto/streams/streams.rs

@@ -909,16 +909,29 @@ fn drop_stream_ref(inner: &Mutex<Inner>, key: store::Key) {
 
     let actions = &mut me.actions;
 
-    me.counts.transition(stream, |counts, mut stream| {
-        if stream.is_canceled_interest() {
-            actions.send.schedule_cancel(
-                &mut stream,
-                &mut actions.task);
-            actions.recv.enqueue_reset_expiration(stream, counts);
+    me.counts.transition(stream, |counts, stream| {
+        maybe_cancel(stream, actions, counts);
+
+        if stream.ref_count == 0 {
+            let mut ppp = stream.pending_push_promises.take();
+            while let Some(promise) = ppp.pop(stream.store_mut()) {
+                counts.transition(promise, |counts, stream| {
+                    maybe_cancel(stream, actions, counts);
+                });
+            }
         }
     });
 }
 
+fn maybe_cancel(stream: &mut store::Ptr, actions: &mut Actions, counts: &mut Counts) {
+    if stream.is_canceled_interest() {
+        actions.send.schedule_cancel(
+            stream,
+            &mut actions.task);
+        actions.recv.enqueue_reset_expiration(stream, counts);
+    }
+}
+
 // ===== impl SendBuffer =====
 
 impl<B> SendBuffer<B> {