methods: http: Drain pending data before selecting

GnuTLS can already have data pending in its buffers, we need
to to drain that first otherwise select() might block
indefinitely.

Gbp-Dch: ignore

3 files changed, 20 insertions, 1 deletions

diff --git a/methods/connect.cc b/methods/connect.cc
index c40f34f2d..e48008214 100644
--- a/methods/connect.cc
+++ b/methods/connect.cc
@@ -98,6 +98,10 @@ struct FdFd : public MethodFd
    }
 };
 
+bool MethodFd::HasPending()
+{
+   return false;
+}
 std::unique_ptr<MethodFd> MethodFd::FromFd(int iFd)
 {
    FdFd *fd = new FdFd();
@@ -626,6 +630,11 @@ struct TlsFd : public MethodFd
 	 return -1;
       return UnderlyingFd->Close();
    }
+
+   bool HasPending() APT_OVERRIDE
+   {
+      return gnutls_record_check_pending(session) > 0;
+   }
 };
 
 bool UnwrapTLS(std::string Host, std::unique_ptr<MethodFd> &Fd,
diff --git a/methods/connect.h b/methods/connect.h
index 39f3c1ce2..4456d660d 100644
--- a/methods/connect.h
+++ b/methods/connect.h
@@ -35,6 +35,8 @@ struct MethodFd
    virtual ~MethodFd(){};
    /// \brief Construct a MethodFd from a UNIX file descriptor
    static std::unique_ptr<MethodFd> FromFd(int iFd);
+   /// \brief If there is pending data.
+   virtual bool HasPending();
 };
 
 bool Connect(std::string To, int Port, const char *Service, int DefPort,
diff --git a/methods/http.cc b/methods/http.cc
index 4d8c0808b..b302c896d 100644
--- a/methods/http.cc
+++ b/methods/http.cc
@@ -621,7 +621,15 @@ bool HttpServerState::Go(bool ToFile, RequestState &Req)
    if (ServerFd->Fd() == -1 && (In.WriteSpace() == false ||
 				ToFile == false))
       return false;
-   
+
+   // Handle server IO
+   if (ServerFd->HasPending() && In.ReadSpace() == true)
+   {
+      errno = 0;
+      if (In.Read(ServerFd) == false)
+	 return Die(Req);
+   }
+
    fd_set rfds,wfds;
    FD_ZERO(&rfds);
    FD_ZERO(&wfds);