MINOR: mux-h2: make sure any h2s always has an endpoint

The principle that each mux stream should have an endpoint is not
guaranteed for closed streams that map to the dummy static streams.
Let's have a dummy endpoint for use with such streams. It only has
the DETACHED flag and a NULL conn_stream, and is referenced by all
the closed streams so that we can afford not to test h2s->endp when
trying to access the flags or the CS.

diff --git a/src/mux_h2.c b/src/mux_h2.c
index 1ff0a97a8b5fa368f1adb6918ff49ebbeb43bbbe..624a1bd7c42cb059bec488a056e57f6dc8902267 100644 (file)
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -523,9 +523,16 @@ static int h2_settings_initial_window_size    = 65535; /* initial value */
 static unsigned int h2_settings_max_concurrent_streams = 100;
 static int h2_settings_max_frame_size         = 0;     /* unset */
 
+/* a dummy closed endpoint */
+static const struct cs_endpoint closed_ep = {
+       . cs       = NULL,
+       .flags     = CS_EP_DETACHED,
+};
+
 /* a dmumy closed stream */
 static const struct h2s *h2_closed_stream = &(const struct h2s){
        .cs        = NULL,
+       .endp      = (struct cs_endpoint *)&closed_ep,
        .h2c       = NULL,
        .st        = H2_SS_CLOSED,
        .errcode   = H2_ERR_STREAM_CLOSED,
@@ -536,6 +543,7 @@ static const struct h2s *h2_closed_stream = &(const struct h2s){
 /* a dmumy closed stream returning a PROTOCOL_ERROR error */
 static const struct h2s *h2_error_stream = &(const struct h2s){
        .cs        = NULL,
+       .endp      = (struct cs_endpoint *)&closed_ep,
        .h2c       = NULL,
        .st        = H2_SS_CLOSED,
        .errcode   = H2_ERR_PROTOCOL_ERROR,
@@ -546,6 +554,7 @@ static const struct h2s *h2_error_stream = &(const struct h2s){
 /* a dmumy closed stream returning a REFUSED_STREAM error */
 static const struct h2s *h2_refused_stream = &(const struct h2s){
        .cs        = NULL,
+       .endp      = (struct cs_endpoint *)&closed_ep,
        .h2c       = NULL,
        .st        = H2_SS_CLOSED,
        .errcode   = H2_ERR_REFUSED_STREAM,
@@ -556,6 +565,7 @@ static const struct h2s *h2_refused_stream = &(const struct h2s){
 /* and a dummy idle stream for use with any unannounced stream */
 static const struct h2s *h2_idle_stream = &(const struct h2s){
        .cs        = NULL,
+       .endp      = (struct cs_endpoint *)&closed_ep,
        .h2c       = NULL,
        .st        = H2_SS_IDLE,
        .errcode   = H2_ERR_STREAM_CLOSED,