XCB: Simplify xcb error handling

Instead of getting errors just to feed them to the default error handle,
the corresponding unchecked request is used which automatically makes
errors go to the default error handler.

Change-Id: Ib213a860affb72de6f9896f68505e283a809d58f
Signed-off-by: Uli Schlachter <psychon@znc.in>
Reviewed-by: Samuel Rødal <samuel.rodal@nokia.com>
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>

1 files changed, 20 insertions, 65 deletions

diff --git a/src/plugins/platforms/xcb/qxcbwindow.cpp b/src/plugins/platforms/xcb/qxcbwindow.cpp
index ba4a6f7c5e..5a8f90b7ad 100644
--- a/src/plugins/platforms/xcb/qxcbwindow.cpp
+++ b/src/plugins/platforms/xcb/qxcbwindow.cpp
@@ -66,6 +66,7 @@
 #ifdef XCB_ICCCM_NUM_WM_SIZE_HINTS_ELEMENTS
 #define xcb_get_wm_hints_reply xcb_icccm_get_wm_hints_reply
 #define xcb_get_wm_hints xcb_icccm_get_wm_hints
+#define xcb_get_wm_hints_unchecked xcb_icccm_get_wm_hints_unchecked
 #define xcb_set_wm_hints xcb_icccm_set_wm_hints
 #define xcb_set_wm_normal_hints xcb_icccm_set_wm_normal_hints
 #define xcb_size_hints_set_base_size xcb_icccm_size_hints_set_base_size
@@ -420,10 +421,9 @@ QMargins QXcbWindow::frameMargins() const
             connection()->wmSupport()->virtualRoots();
 
         while (!foundRoot) {
-            xcb_query_tree_cookie_t cookie = xcb_query_tree(xcb_connection(), parent);
+            xcb_query_tree_cookie_t cookie = xcb_query_tree_unchecked(xcb_connection(), parent);
 
-            xcb_generic_error_t *error;
-            xcb_query_tree_reply_t *reply = xcb_query_tree_reply(xcb_connection(), cookie, &error);
+            xcb_query_tree_reply_t *reply = xcb_query_tree_reply(xcb_connection(), cookie, NULL);
             if (reply) {
                 if (reply->root == reply->parent || virtualRoots.indexOf(reply->parent) != -1) {
                     foundRoot = true;
@@ -434,11 +434,6 @@ QMargins QXcbWindow::frameMargins() const
 
                 free(reply);
             } else {
-                if (error) {
-                    connection()->handleXcbError(error);
-                    free(error);
-                }
-
                 m_dirtyFrameMargins = false;
                 m_frameMargins = QMargins();
                 return m_frameMargins;
@@ -447,25 +442,22 @@ QMargins QXcbWindow::frameMargins() const
 
         QPoint offset;
 
-        xcb_generic_error_t *error;
         xcb_translate_coordinates_reply_t *reply =
             xcb_translate_coordinates_reply(
                 xcb_connection(),
                 xcb_translate_coordinates(xcb_connection(), window, parent, 0, 0),
-                &error);
+                NULL);
 
         if (reply) {
             offset = QPoint(reply->dst_x, reply->dst_y);
             free(reply);
-        } else if (error) {
-            free(error);
         }
 
         xcb_get_geometry_reply_t *geom =
             xcb_get_geometry_reply(
                 xcb_connection(),
                 xcb_get_geometry(xcb_connection(), parent),
-                &error);
+                NULL);
 
         if (geom) {
             // --
@@ -485,8 +477,6 @@ QMargins QXcbWindow::frameMargins() const
             m_frameMargins = QMargins(left, top, right, bottom);
 
             free(geom);
-        } else if (error) {
-            free(error);
         }
 
         m_dirtyFrameMargins = false;
@@ -506,17 +496,10 @@ void QXcbWindow::setVisible(bool visible)
 void QXcbWindow::show()
 {
     if (window()->isTopLevel()) {
-        xcb_get_property_cookie_t cookie = xcb_get_wm_hints(xcb_connection(), m_window);
-
-        xcb_generic_error_t *error;
+        xcb_get_property_cookie_t cookie = xcb_get_wm_hints_unchecked(xcb_connection(), m_window);
 
         xcb_wm_hints_t hints;
-        xcb_get_wm_hints_reply(xcb_connection(), cookie, &hints, &error);
-
-        if (error) {
-            connection()->handleXcbError(error);
-            free(error);
-        }
+        xcb_get_wm_hints_reply(xcb_connection(), cookie, &hints, NULL);
 
         if (window()->windowState() & Qt::WindowMinimized)
             xcb_wm_hints_set_iconic(&hints);
@@ -616,20 +599,15 @@ static QtMotifWmHints getMotifWmHints(QXcbConnection *c, xcb_window_t window)
     QtMotifWmHints hints;
 
     xcb_get_property_cookie_t get_cookie =
-        xcb_get_property(c->xcb_connection(), 0, window, c->atom(QXcbAtom::_MOTIF_WM_HINTS),
+        xcb_get_property_unchecked(c->xcb_connection(), 0, window, c->atom(QXcbAtom::_MOTIF_WM_HINTS),
                          c->atom(QXcbAtom::_MOTIF_WM_HINTS), 0, 20);
 
-    xcb_generic_error_t *error;
-
     xcb_get_property_reply_t *reply =
-        xcb_get_property_reply(c->xcb_connection(), get_cookie, &error);
+        xcb_get_property_reply(c->xcb_connection(), get_cookie, NULL);
 
     if (reply && reply->format == 32 && reply->type == c->atom(QXcbAtom::_MOTIF_WM_HINTS)) {
         hints = *((QtMotifWmHints *)xcb_get_property_value(reply));
-    } else if (error) {
-        c->handleXcbError(error);
-        free(error);
-
+    } else {
         hints.flags = 0L;
         hints.functions = MWM_FUNC_ALL;
         hints.decorations = MWM_DECOR_ALL;
@@ -683,13 +661,11 @@ QVector<xcb_atom_t> QXcbWindow::getNetWmState()
     QVector<xcb_atom_t> result;
 
     xcb_get_property_cookie_t get_cookie =
-        xcb_get_property(xcb_connection(), 0, m_window, atom(QXcbAtom::_NET_WM_STATE),
+        xcb_get_property_unchecked(xcb_connection(), 0, m_window, atom(QXcbAtom::_NET_WM_STATE),
                          XCB_ATOM_ATOM, 0, 1024);
 
-    xcb_generic_error_t *error;
-
     xcb_get_property_reply_t *reply =
-        xcb_get_property_reply(xcb_connection(), get_cookie, &error);
+        xcb_get_property_reply(xcb_connection(), get_cookie, NULL);
 
     if (reply && reply->format == 32 && reply->type == XCB_ATOM_ATOM) {
         result.resize(reply->length);
@@ -702,9 +678,6 @@ QVector<xcb_atom_t> QXcbWindow::getNetWmState()
 #endif
 
         free(reply);
-    } else if (error) {
-        connection()->handleXcbError(error);
-        free(error);
     } else {
 #ifdef NET_WM_STATE_DEBUG
         printf("getting net wm state (%x), empty\n", m_window);
@@ -1084,16 +1057,10 @@ void QXcbWindow::setTransparentForMouseEvents(bool transparent)
 
 void QXcbWindow::updateDoesNotAcceptFocus(bool doesNotAcceptFocus)
 {
-    xcb_get_property_cookie_t cookie = xcb_get_wm_hints(xcb_connection(), m_window);
-
-    xcb_generic_error_t *error;
+    xcb_get_property_cookie_t cookie = xcb_get_wm_hints_unchecked(xcb_connection(), m_window);
 
     xcb_wm_hints_t hints;
-    xcb_get_wm_hints_reply(xcb_connection(), cookie, &hints, &error);
-
-    if (error) {
-        connection()->handleXcbError(error);
-        free(error);
+    if (!xcb_get_wm_hints_reply(xcb_connection(), cookie, &hints, NULL)) {
         return;
     }
 
@@ -1314,14 +1281,11 @@ void QXcbWindow::handleConfigureNotifyEvent(const xcb_configure_notify_event_t *
         // Do not trust the position, query it instead.
         xcb_translate_coordinates_cookie_t cookie = xcb_translate_coordinates(xcb_connection(), xcb_window(),
                                                                               m_screen->root(), 0, 0);
-        xcb_generic_error_t *error;
-        xcb_translate_coordinates_reply_t *reply = xcb_translate_coordinates_reply(xcb_connection(), cookie, &error);
+        xcb_translate_coordinates_reply_t *reply = xcb_translate_coordinates_reply(xcb_connection(), cookie, NULL);
         if (reply) {
             pos.setX(reply->dst_x);
             pos.setY(reply->dst_y);
             free(reply);
-        } else if (error) {
-            free(error);
         }
     }
 
@@ -1498,19 +1462,14 @@ void QXcbWindow::handlePropertyNotifyEvent(const xcb_property_notify_event_t *ev
             xcb_get_property(xcb_connection(), 0, m_window, atom(QXcbAtom::WM_STATE),
                              XCB_ATOM_ANY, 0, 1024);
 
-        xcb_generic_error_t *error;
-
         xcb_get_property_reply_t *reply =
-            xcb_get_property_reply(xcb_connection(), get_cookie, &error);
+            xcb_get_property_reply(xcb_connection(), get_cookie, NULL);
 
         xcb_atom_t wm_state = XCB_WM_STATE_WITHDRAWN;
         if (reply && reply->format == 32 && reply->type == atom(QXcbAtom::WM_STATE)) {
             if (reply->length != 0)
                 wm_state = ((long *)xcb_get_property_value(reply))[0];
             free(reply);
-        } else if (error) {
-            connection()->handleXcbError(error);
-            free(error);
         }
 
         QVector<xcb_atom_t> netWmState = getNetWmState();
@@ -1576,11 +1535,9 @@ bool QXcbWindow::setKeyboardGrabEnabled(bool grab)
     xcb_grab_keyboard_cookie_t cookie = xcb_grab_keyboard(xcb_connection(), false,
                                                           m_window, XCB_TIME_CURRENT_TIME,
                                                           XCB_GRAB_MODE_ASYNC, XCB_GRAB_MODE_ASYNC);
-    xcb_generic_error_t *err;
-    xcb_grab_keyboard_reply_t *reply = xcb_grab_keyboard_reply(xcb_connection(), cookie, &err);
-    bool result = !(err || !reply || reply->status != XCB_GRAB_STATUS_SUCCESS);
+    xcb_grab_keyboard_reply_t *reply = xcb_grab_keyboard_reply(xcb_connection(), cookie, NULL);
+    bool result = !(!reply || reply->status != XCB_GRAB_STATUS_SUCCESS);
     free(reply);
-    free(err);
     return result;
 }
 
@@ -1597,11 +1554,9 @@ bool QXcbWindow::setMouseGrabEnabled(bool grab)
                                                         XCB_GRAB_MODE_ASYNC, XCB_GRAB_MODE_ASYNC,
                                                         XCB_WINDOW_NONE, XCB_CURSOR_NONE,
                                                         XCB_TIME_CURRENT_TIME);
-    xcb_generic_error_t *err;
-    xcb_grab_pointer_reply_t *reply = xcb_grab_pointer_reply(xcb_connection(), cookie, &err);
-    bool result = !(err || !reply || reply->status != XCB_GRAB_STATUS_SUCCESS);
+    xcb_grab_pointer_reply_t *reply = xcb_grab_pointer_reply(xcb_connection(), cookie, NULL);
+    bool result = !(!reply || reply->status != XCB_GRAB_STATUS_SUCCESS);
     free(reply);
-    free(err);
     return result;
 }