Implement provably-correct sequence wrap handling. Add flag XCB_REQUEST_DISCARD_REPLY.

[free-sw/xcb/libxcb] / src / xcb_in.c

diff --git a/src/xcb_in.c b/src/xcb_in.c
index cf7dbe7..ea851c7 100644 (file)
--- a/src/xcb_in.c
+++ b/src/xcb_in.c
@@ -91,6 +91,8 @@ static int read_packet(XCBConnection *c)
         c->in.request_read = (lastread & 0xffff0000) | genrep.sequence;
         if(c->in.request_read < lastread)
             c->in.request_read += 0x10000;
+        if(c->in.request_read > c->in.request_expected)
+            c->in.request_expected = c->in.request_read;
 
         if(c->in.request_read != lastread)
         {
@@ -141,6 +143,11 @@ static int read_packet(XCBConnection *c)
         free(buf);
         return 0;
     }
+    if(pend && (pend->flags & XCB_REQUEST_DISCARD_REPLY))
+    {
+        free(buf);
+        return 1;
+    }
 
     if(genrep.response_type != 1)
         ((XCBGenericEvent *) buf)->full_sequence = c->in.request_read;
@@ -238,6 +245,10 @@ void *XCBWaitForReply(XCBConnection *c, unsigned int request, XCBGenericError **
     if(e)
         *e = 0;
 
+    /* If an error occurred when issuing the request, fail immediately. */
+    if(!request)
+        return 0;
+
     pthread_mutex_lock(&c->iolock);
 
     /* If this request has not been written yet, write it. */