Error.c: In function ‘nxagentGetSessionPath’:
Error.c:543:62: warning: ‘%s’ directive output may be truncated writing up to 255 bytes into a region of size 253 [-Wformat-truncation=]
     snprintf(nxagentSessionDir, DEFAULT_STRING_LENGTH, "%s/C-%s", rootPath, nxagentSessionId);
                                                              ^~             ~~~~~~~~~~~~~~~~
Error.c:543:5: note: ‘snprintf’ output 4 or more bytes (assuming 259) into a destination of size 256
     snprintf(nxagentSessionDir, DEFAULT_STRING_LENGTH, "%s/C-%s", rootPath, nxagentSessionId);
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Dialog.c: In function ‘nxagentLaunchDialog’:
Dialog.c:320:53: warning: ‘%s’ directive output may be truncated writing up to 1023 bytes into a region of size 256 [-Wformat-truncation=]
     snprintf(dialogDisplay, sizeof(dialogDisplay), "%s", nxagentDisplayName);
                                                     ^~   ~~~~~~~~~~~~~~~~~~
Dialog.c:320:5: note: ‘snprintf’ output between 1 and 1024 bytes into a destination of size 256
     snprintf(dialogDisplay, sizeof(dialogDisplay), "%s", nxagentDisplayName);
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

XlibAtom should be used wherever remote atoms are handled. This is
important as Xlib data types and server data types of the same name do
not always have identical sizes.

See also https://lists.freedesktop.org/archives/xorg-devel/2015-August/047245.html