1 files changed, 32 insertions, 12 deletions

diff --git a/libxcb/src/xcb_xid.c b/libxcb/src/xcb_xid.c
index 7ff0c5fc2..3df5dbec6 100644
--- a/libxcb/src/xcb_xid.c
+++ b/libxcb/src/xcb_xid.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001-2004 Bart Massey and Jamey Sharp.
+/* Copyright (C) 2001-2008 Bart Massey and Jamey Sharp.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -25,6 +25,7 @@
 
 /* XID allocators. */
 
+#include <assert.h>
 #include <stdlib.h>
 #include "xcb.h"
 #include "xcbext.h"
@@ -39,21 +40,40 @@ uint32_t xcb_generate_id(xcb_connection_t *c)
     if(c->has_error)
         return -1;
     pthread_mutex_lock(&c->xid.lock);
-    if(c->xid.last == c->xid.max)
+    if(c->xid.last >= c->xid.max - c->xid.inc + 1)
     {
         xcb_xc_misc_get_xid_range_reply_t *range;
-        range = xcb_xc_misc_get_xid_range_reply(c, xcb_xc_misc_get_xid_range(c), 0);
-        if(!range)
-        {
-            pthread_mutex_unlock(&c->xid.lock);
-            return -1;
+        assert(c->xid.last == c->xid.max);
+        if (c->xid.last == 0) {
+            /* finish setting up initial range */
+            c->xid.max = c->setup->resource_id_mask;
+        } else {
+            /* check for extension */
+            const xcb_query_extension_reply_t *xc_misc_reply =
+              xcb_get_extension_data(c, &xcb_xc_misc_id);
+            if (!xc_misc_reply) {
+                pthread_mutex_unlock(&c->xid.lock);
+                return -1;
+            }
+            /* get new range */
+            range = xcb_xc_misc_get_xid_range_reply(c,
+                      xcb_xc_misc_get_xid_range(c), 0);
+            /* XXX The latter disjunct is what the server returns
+               when it is out of XIDs.  Sweet. */
+            if(!range || (range->start_id == 0 && range->count == 1))
+            {
+                pthread_mutex_unlock(&c->xid.lock);
+                return -1;
+            }
+            assert(range->count > 0 && range->start_id > 0);
+            c->xid.last = range->start_id;
+            c->xid.max = range->start_id + (range->count - 1) * c->xid.inc;
+            free(range);
         }
-        c->xid.last = range->start_id;
-        c->xid.max = range->start_id + (range->count - 1) * c->xid.inc;
-        free(range);
+    } else {
+        c->xid.last += c->xid.inc;
     }
     ret = c->xid.last | c->xid.base;
-    c->xid.last += c->xid.inc;
     pthread_mutex_unlock(&c->xid.lock);
     return ret;
 }
@@ -65,8 +85,8 @@ int _xcb_xid_init(xcb_connection_t *c)
     if(pthread_mutex_init(&c->xid.lock, 0))
         return 0;
     c->xid.last = 0;
+    c->xid.max = 0;
     c->xid.base = c->setup->resource_id_base;
-    c->xid.max = c->setup->resource_id_mask;
     c->xid.inc = c->setup->resource_id_mask & -(c->setup->resource_id_mask);
     return 1;
 }