From 9464458098da637aa642917c782fa56bc9682802 Mon Sep 17 00:00:00 2001 From: Uli Schlachter Date: Sat, 28 Jan 2012 22:35:15 +0100 Subject: xcb: Check for SHM extension before using it MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If we call any xcb_shm_*() function, libxcb will have to figure out SHM's major number. However, if that fails because the SHM extension is not available, xcb will disconnect from the server. Obviously, that's not what we want and must be avoided. Change-Id: I8eba5ff9e84e0e2017a5c0d88fda4efd0459bd1e Signed-off-by: Uli Schlachter Reviewed-by: Samuel Rødal --- src/plugins/platforms/xcb/qxcbbackingstore.cpp | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'src/plugins/platforms/xcb') diff --git a/src/plugins/platforms/xcb/qxcbbackingstore.cpp b/src/plugins/platforms/xcb/qxcbbackingstore.cpp index 76304be541..b7369525a5 100644 --- a/src/plugins/platforms/xcb/qxcbbackingstore.cpp +++ b/src/plugins/platforms/xcb/qxcbbackingstore.cpp @@ -115,8 +115,12 @@ QXcbShmImage::QXcbShmImage(QXcbScreen *screen, const QSize &size, uint depth, QI m_shm_info.shmaddr = m_xcb_image->data = (quint8 *)shmat (m_shm_info.shmid, 0, 0); m_shm_info.shmseg = xcb_generate_id(xcb_connection()); - xcb_generic_error_t *error = xcb_request_check(xcb_connection(), xcb_shm_attach_checked(xcb_connection(), m_shm_info.shmseg, m_shm_info.shmid, false)); - if (error) { + const xcb_query_extension_reply_t *shm_reply = xcb_get_extension_data(xcb_connection(), &xcb_shm_id); + bool shm_present = shm_reply != NULL && shm_reply->present; + xcb_generic_error_t *error = NULL; + if (shm_present) + error = xcb_request_check(xcb_connection(), xcb_shm_attach_checked(xcb_connection(), m_shm_info.shmseg, m_shm_info.shmid, false)); + if (!shm_present || error) { free(error); shmdt(m_shm_info.shmaddr); -- cgit v1.2.3