Synergy drops connections intermittently

I have a similar problem, also using Ubuntu 8.04 with Gnome as the server and Windows XP SP2 as the client. The problem seems to be that the synergys server on Ubuntu dies. The log files shows a segmentation fault (see below). It happens when simply moving from one screen to another not when trying to copy/paste, although there is something in the copy/paste buffer.

INFO: CServer.cpp,446: switch from "WindowsXPClient" to "UbuntuServer" at 1,567
INFO: CScreen.cpp,98: entering screen
INFO: CServer.cpp,446: switch from "UbuntuServer" to "WindowsXPClient" at 2303,697
INFO: CScreen.cpp,116: leaving screen
DEBUG: CXWindowsClipboard.cpp,313: open clipboard 0
DEBUG: CXWindowsClipboard.cpp,493: ICCCM fill clipboard 0
DEBUG: CXWindowsClipboard.cpp,512: available targets: STRING (31)
DEBUG: CXWindowsClipboard.cpp,348: close clipboard 0
DEBUG: CServer.cpp,1434: ignored screen "UbuntuServer" update of clipboard 0 (unchanged)
DEBUG: CXWindowsClipboard.cpp,313: open clipboard 1
DEBUG: CXWindowsClipboard.cpp,493: ICCCM fill clipboard 1
DEBUG: CXWindowsClipboard.cpp,512: available targets: STRING (31)
DEBUG: CXWindowsClipboard.cpp,348: close clipboard 1
DEBUG: CServer.cpp,1434: ignored screen "UbuntuServer" update of clipboard 1 (unchanged)
INFO: CServer.cpp,446: switch from "WindowsXPClient" to "UbuntuServer" at 1,699
INFO: CScreen.cpp,98: entering screen
INFO: CServer.cpp,446: switch from "UbuntuServer" to "WindowsXPClient" at 2303,596
INFO: CScreen.cpp,116: leaving screen
DEBUG: CXWindowsClipboard.cpp,313: open clipboard 0
DEBUG: CXWindowsClipboard.cpp,493: ICCCM fill clipboard 0
DEBUG: CXWindowsClipboard.cpp,512: available targets: STRING (31)
DEBUG: CXWindowsClipboard.cpp,348: close clipboard 0
DEBUG: CServer.cpp,1434: ignored screen "UbuntuServer" update of clipboard 0 (unchanged)
DEBUG: CXWindowsClipboard.cpp,313: open clipboard 1
DEBUG: CXWindowsClipboard.cpp,493: ICCCM fill clipboard 1
DEBUG: CXWindowsClipboard.cpp,512: available targets: STRING (31)
DEBUG: CXWindowsClipboard.cpp,348: close clipboard 1
DEBUG: CServer.cpp,1434: ignored screen "UbuntuServer" update of clipboard 1 (unchanged)
DEBUG: CClientProxy1_0.cpp,466: received client "WindowsXPClient" grabbed clipboard 0 seqnum=43
DEBUG: CClientProxy1_0.cpp,466: received client "WindowsXPClient" grabbed clipboard 1 seqnum=43
INFO: CServer.cpp,1185: screen "WindowsXPClient" grabbed clipboard 0 from "UbuntuServer"
DEBUG: CXWindowsClipboard.cpp,313: open clipboard 0
DEBUG: CXWindowsClipboard.cpp,266: empty clipboard 0
DEBUG: CXWindowsClipboard.cpp,289: grabbed clipboard 0
DEBUG: CXWindowsClipboard.cpp,348: close clipboard 0
INFO: CServer.cpp,1185: screen "WindowsXPClient" grabbed clipboard 1 from "UbuntuServer"
DEBUG: CXWindowsClipboard.cpp,313: open clipboard 1
DEBUG: CXWindowsClipboard.cpp,266: empty clipboard 1
DEBUG: CXWindowsClipboard.cpp,289: grabbed clipboard 1
DEBUG: CXWindowsClipboard.cpp,348: close clipboard 1
Segmentation fault

I don't have the debug output but i have similar behavior on two Hardy machines... periodically my client freezes for a few seconds, like it has to reconnect to the server.

I had this problem under Gutsy Gibbon, except I could get around it by running synergyc and syngerys with sudo. in Hardy running with sudo does't make a difference....

I have the same problem. Here is the last part of my debug log. I'm using a pretty vanilla version of Hardy. I know some people are having this problem when using klipper, but i'm not using anything like that. Any suggestions?

DEBUG: CXWindowsClipboard.cpp,313: open clipboard 0
DEBUG: CXWindowsClipboard.cpp,493: ICCCM fill clipboard 0
DEBUG: CXWindowsClipboard.cpp,512: available targets: TIMESTAMP (248), TARGETS (246), MULTIPLE (247), text/html (257), text/_moz_htmlcontext (454), text/_moz_
htmlinfo (455), UTF8_STRING (260), COMPOUND_TEXT (297), TEXT (453), STRING (31), text/x-moz-url-priv (456)
DEBUG: CXWindowsClipboard.cpp,555: added format 2 for target text/html (257) (50 bytes)
DEBUG: CXWindowsClipboard.cpp,555: added format 0 for target UTF8_STRING (260) (24 bytes)
DEBUG: CXWindowsClipboard.cpp,348: close clipboard 0
DEBUG: CXWindowsClipboard.cpp,313: open clipboard 1
DEBUG: CXWindowsClipboard.cpp,493: ICCCM fill clipboard 1
DEBUG: CXWindowsClipboard.cpp,512: available targets: TIMESTAMP (248), TARGETS (246), MULTIPLE (247), text/html (257), text/_moz_htmlcontext (454), text/_moz_htmlinfo (455), UTF8_STRING (260), COMPOUND_TEXT (297), TEXT (453), STRING (31),
 text/x-moz-url-priv (456)
DEBUG: CXWindowsClipboard.cpp,555: added format 2 for target text/html (257) (50 bytes)
DEBUG: CXWindowsClipboard.cpp,555: added format 0 for target UTF8_STRING (260) (24 bytes)
DEBUG: CXWindowsClipboard.cpp,348: close clipboard 1
DEBUG: CServerProxy.cpp,542: recv grab clipboard 0
DEBUG: CXWindowsClipboard.cpp,313: open clipboard 0
DEBUG: CXWindowsClipboard.cpp,266: empty clipboard 0
DEBUG: CXWindowsClipboard.cpp,289: grabbed clipboard 0
DEBUG: CXWindowsClipboard.cpp,348: close clipboard 0
DEBUG: CServerProxy.cpp,542: recv grab clipboard 1
DEBUG: CXWindowsClipboard.cpp,313: open clipboard 1
DEBUG: CXWindowsClipboard.cpp,266: empty clipboard 1
DEBUG: CXWindowsClipboard.cpp,289: grabbed clipboard 1
DEBUG: CXWindowsClipboard.cpp,348: close clipboard 1
Segmentation fault

Please obtain a stacktrace for this segv. You can do that by:

1. create a new folder
2. use "apt-get source synergy" to get the code
3. move into the synergy dir and type this command to rebuild the code with full debug symbols and no optimizations:

DEB_BUILD_OPTIONS="noopt nostrip" fakeroot debian/rules binary

4. then do "cd .."
5. and finally "sudo dpkg -i *.deb" to install the new version
6. now for example the synergy client under valgrind like this:

valgrind synergyc --no-daemon your_server_hostname

Hopefully you will see the stacktrace printed there with symbols and stuff... please paste it into this bug report.

INFO: CScreen.cpp,98: entering screen
DEBUG: CServerProxy.cpp,523: recv clipboard 0 size=116
DEBUG: CXWindowsClipboard.cpp,313: open clipboard 0
DEBUG: CXWindowsClipboard.cpp,266: empty clipboard 0
DEBUG: CXWindowsClipboard.cpp,289: grabbed clipboard 0
DEBUG: CXWindowsClipboard.cpp,300: add 104 bytes to clipboard 0 format: 0
DEBUG: CXWindowsClipboard.cpp,348: close clipboard 0
DEBUG: CServerProxy.cpp,523: recv clipboard 1 size=116
DEBUG: CXWindowsClipboard.cpp,313: open clipboard 1
DEBUG: CXWindowsClipboard.cpp,266: empty clipboard 1
DEBUG: CXWindowsClipboard.cpp,289: grabbed clipboard 1
DEBUG: CXWindowsClipboard.cpp,300: add 104 bytes to clipboard 1 format: 0
DEBUG: CXWindowsClipboard.cpp,348: close clipboard 1
INFO: CScreen.cpp,116: leaving screen
INFO: CScreen.cpp,98: entering screen
synergyc: ../../src/xcb_lock.c:77: _XGetXCBBuffer: Assertion `((int) ((xcb_req) - (dpy->request)) >= 0)' failed.
==23029==
==23029== ERROR SUMMARY: 63 errors from 3 contexts (suppressed: 1862 from 3)
==23029== malloc/free: in use at exit: 201,356 bytes in 4,798 blocks.
==23029== malloc/free: 37,762 allocs, 32,964 frees, 1,060,808 bytes allocated.
==23029== For counts of detected errors, rerun with: -v
==23029== searching for pointers to 4,798 not-freed blocks.
==23029== checked 17,154,524 bytes.
==23029==
==23029== LEAK SUMMARY:
==23029== definitely lost: 0 bytes in 0 blocks.
==23029== possibly lost: 2,626 bytes in 37 blocks.
==23029== still reachable: 198,730 bytes in 4,761 blocks.
==23029== suppressed: 0 bytes in 0 blocks.
==23029== Rerun with --leak-check=full to see details of leaked memory.
Killed

Here's the valgrind output with additional flags (as suggested by valgrind)

Same problem here: Ubuntu Linux 2.6.24.3 #1 SMP PREEMPT i686

DEBUG1: CKeyMap.cpp,101: add key: ef09 3 017 0000 (0001 0001 0000)
DEBUG1: CKeyState.cpp,492: modifiers on update: 0x2000
DEBUG: CXWindowsClipboard.cpp,313: open clipboard 0
DEBUG1: CXWindowsClipboard.cpp,621: locked motif clipboard
DEBUG2: CXWindowsUtil.cpp,1352: can't read property 359 on window 0x0000015b
DEBUG1: CXWindowsClipboard.cpp,327: motif does not own clipboard
DEBUG1: CXWindowsClipboard.cpp,628: unlocked motif clipboard
DEBUG: CXWindowsClipboard.cpp,266: empty clipboard 0
DEBUG: CXWindowsClipboard.cpp,289: grabbed clipboard 0
DEBUG: CXWindowsClipboard.cpp,348: close clipboard 0
DEBUG: CXWindowsClipboard.cpp,313: open clipboard 1
DEBUG: CXWindowsClipboard.cpp,266: empty clipboard 1
DEBUG: CXWindowsClipboard.cpp,289: grabbed clipboard 1
DEBUG: CXWindowsClipboard.cpp,348: close clipboard 1
DEBUG1: CXWindowsClipboard.cpp,118: request for clipboard 248, target TARGETS (250) by 0x03200035 (property=_QT_SELECTION (254))
DEBUG1: CXWindowsClipboard.cpp,135: failed, not owned at time 510824066
DEBUG1: CXWindowsClipboard.cpp,141: failed
DEBUG1: CXWindowsClipboard.cpp,1030: clipboard: sending failure to 0x03200035,250,0
Erreur de segmentation

Found a patch for this on the redhat bugtracker: https://bugzilla.redhat.com/show_bug.cgi?id=434539#c11 Reading the comments below the patch seems to work well.

Thank you for reporting this bug to Ubuntu. Hardy reached EOL on May 12, 2011.
Please see this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

I've tried recreating this bug with Oneiric and was unable to, given the information you've provided. Please either a) upgrade and test or b) increase the verbosity of the steps to recreate it so we can try again.

Please feel free to report any other bugs you may find.