Updated tigervnc packages that fix several bugs are now available for Red Hat Enterprise Linux 6.
Virtual Network Computing (VNC) is a remote display system which allows users to view a computing desktop environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures.
- When more than one display was configured in the /etc/sysconfig/vncservers file, the vncserver initscript could stop, preventing other displays from being started. The source code has been fixed, and vncserver now attempts to start each configured display as intended.
- The position of the mouse cursor in the VNC session was not correctly communicated to the VNC viewer, resulting in cursor misplacements. The method of displaying the remote cursor has been changed, and cursor movements on VNC server are now accurately reflected on VNC client.
- BZ#917717, BZ#991285
- Previously, incompatible versions of pixman, libX11, and tigervnc-server utilities could be installed on Xvnc. Nevertheless, Xvnc could not start due to symbol resolution failures or crashes. With this update, tigervnc-server has explicit version requirements for pixman and libX11, and Xvnc now starts successfully.
- The vncserver initscript made an assumption about the preferred shell for users of TigerVNC. As a consequence, configured displays started only for users using bash. The underlying source code has been fixed, and configured displays now start for any shell the user chooses.
- Previously, Xvnc created via the xinetd daemon a random connection that was not invoked by the user, consuming abundant CPU memory. A problem with running Xvnc from x/inetd in the "nowait" mode has been fixed, and user or non-user Xvnc connections no longer lead to high CPU usage.
- Drawing operations on window borders accessed the pixmap screen directly with Xvnc assuming that all drawing operations operated on a window. This could lead to artifacts on the screen. A fix has been back-ported from upstream, and anomalies no longer occur during visual representation.
- Previously, the VNC Xorg extension could be initialized twice, leading to a busy loop on exit. An upstream patch has been back-ported to allow initialization only once.
- When using TigerVNC with certain keyboard layouts, the AltGr key did not work, preventing users from producing symbols such as "@" (at-sign). A fix from a later version of tigervnc has been back-ported, and AltGr key combinations now work correctly.
- Due to differences in keyboard mappings, keypresses over VNC sometimes needed to be sent using a fake shift keypress. When using keys on the numeric keypad with NumLock active, this approach did not work. With this update, a fix has been back-ported to avoid using fake shift keypresses for numeric keypad keys, and the numeric keypad now works correctly when using VNC.
- When using TigerVNC as a loadable X module, initialization of the GLX extension was not performed correctly. This could lead to the X server unexpected termination. A fix from a later version of TigerVNC has been back-ported, and the GLX extension is now initialized correctly.
- When the last X client disconnected, the X server regenerated and all input devices and extensions were reinitialized. Nevertheless, the VNC extension module left the VNC extension inactive. With this update, VNC is retained or re-loaded after server regeneration, and a remote system connects to X server over VNC successfully.
- When negotiating which encoding to use, the vncviewer utility did not validate server-provided encoding values correctly. This caused a write to an array index outside the correct range, leading to a crash. With this update, the encoding values are now correctly validated, preventing such crashes.
Users of tigervnc are advised to upgrade to these updated packages, which fix these bugs.