From db8c109817c9f02b34bef33e3eb7403fb17a6fd6 Mon Sep 17 00:00:00 2001
From: Sean McArthur <sean@seanmonstar.com>
Date: Tue, 19 Sep 2017 14:16:32 -0700
Subject: [PATCH] Client::poll_ready() returns an Error if next stream ID would
 overflow (#103)

Closes #102
---
 src/client.rs                | 2 +-
 src/proto/connection.rs      | 2 +-
 src/proto/streams/send.rs    | 6 +++++-
 src/proto/streams/streams.rs | 6 ++++--
 tests/client_request.rs      | 7 ++++++-
 5 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/src/client.rs b/src/client.rs
index 1a185a9..cee5f99 100644
--- a/src/client.rs
+++ b/src/client.rs
@@ -91,7 +91,7 @@ where
     /// Returns `Ready` when the connection can initialize a new HTTP 2.0
     /// stream.
     pub fn poll_ready(&mut self) -> Poll<(), ::Error> {
-        Ok(self.connection.poll_send_request_ready())
+        self.connection.poll_send_request_ready()
     }
 
     /// Send a request on a new HTTP 2.0 stream
diff --git a/src/proto/connection.rs b/src/proto/connection.rs
index f871f5e..23d48ef 100644
--- a/src/proto/connection.rs
+++ b/src/proto/connection.rs
@@ -250,7 +250,7 @@ where
     B: IntoBuf,
 {
     /// Returns `Ready` when new the connection is able to support a new request stream.
-    pub fn poll_send_request_ready(&mut self) -> Async<()> {
+    pub fn poll_send_request_ready(&mut self) -> Poll<(), ::Error> {
         self.streams.poll_send_request_ready()
     }
 
diff --git a/src/proto/streams/send.rs b/src/proto/streams/send.rs
index b8053bb..114c43d 100644
--- a/src/proto/streams/send.rs
+++ b/src/proto/streams/send.rs
@@ -299,6 +299,10 @@ where
         Ok(())
     }
 
+    pub fn ensure_next_stream_id(&self) -> Result<StreamId, UserError> {
+        self.next_stream_id.map_err(|_| OverflowedStreamId)
+    }
+
     /// Returns a new StreamId if the local actor can initiate a new stream.
     fn try_open(&self) -> Result<StreamId, UserError> {
         if P::is_server() {
@@ -306,6 +310,6 @@ where
             return Err(UnexpectedFrameType);
         }
 
-        self.next_stream_id.map_err(|_| OverflowedStreamId)
+        self.ensure_next_stream_id()
     }
 }
diff --git a/src/proto/streams/streams.rs b/src/proto/streams/streams.rs
index 717de81..c199ea5 100644
--- a/src/proto/streams/streams.rs
+++ b/src/proto/streams/streams.rs
@@ -403,11 +403,13 @@ impl<B> Streams<B, client::Peer>
 where
     B: Buf,
 {
-    pub fn poll_send_request_ready(&mut self) -> Async<()> {
+    pub fn poll_send_request_ready(&mut self) -> Poll<(), ::Error> {
         let mut me = self.inner.lock().unwrap();
         let me = &mut *me;
 
-        me.counts.poll_open_ready()
+        me.actions.send.ensure_next_stream_id()?;
+
+        Ok(me.counts.poll_open_ready())
     }
 }
 
diff --git a/tests/client_request.rs b/tests/client_request.rs
index 4f3b952..ec4c721 100644
--- a/tests/client_request.rs
+++ b/tests/client_request.rs
@@ -85,7 +85,12 @@ fn request_stream_id_overflows() {
                 .body(())
                 .unwrap();
 
-            // second cant use the next stream id, it's over
+
+            // second cannot use the next stream id, it's over
+
+            let poll_err = h2.poll_ready().unwrap_err();
+            assert_eq!(poll_err.to_string(), "user error: stream ID overflowed");
+
             let err = h2.send_request(request, true).unwrap_err();
             assert_eq!(err.to_string(), "user error: stream ID overflowed");