The seg fault cause:
Breakpoint 1, QXcbConnection::initializeXFixes (this=0x1fbc88) at qxcbconnection.cpp:1042 1042 { (gdb) l 1037 xcb_get_input_focus_cookie_t cookie = Q_XCB_CALL(xcb_get_input_focus(xcb_connection())); 1038 free(xcb_get_input_focus_reply(xcb_connection(), cookie, 0)); 1039 } 1040 1041 void QXcbConnection::initializeXFixes() 1042 { 1043 xcb_generic_error_t *error = 0; 1044 const xcb_query_extension_reply_t *reply = xcb_get_extension_data(m_connection, &xcb_xfixes_id); 1045 xfixes_first_event = reply->first_event; 1046 (gdb) n [Thread 0xb10b0460 (LWP 8635) exited] 1044 const xcb_query_extension_reply_t *reply = xcb_get_extension_data(m_connection, &xcb_xfixes_id); (gdb) p m_connection $1 = (xcb_connection_t *) 0x1fc9b0 (gdb) p xcb_xfixes_id $2 = {name = 0xb2433b28 "XFIXES", global_id = 2} (gdb) n 1045 xfixes_first_event = reply->first_event; (gdb) p reply $3 = (const xcb_query_extension_reply_t *) 0x0
Qt expects the first call to 'xcb_get_extension_data' to return a valid pointer, but in this case it's just returning NULL, breaking it up later on.
The seg fault cause:
Breakpoint 1, QXcbConnection: :initializeXFix es (this=0x1fbc88) at qxcbconnection. cpp:1042 input_focus_ cookie_ t cookie = Q_XCB_CALL( xcb_get_ input_focus( xcb_connection( ))); get_input_ focus_reply( xcb_connection( ), cookie, 0)); :initializeXFix es() extension_ reply_t *reply = xcb_get_ extension_ data(m_ connection, &xcb_xfixes_id); extension_ reply_t *reply = xcb_get_ extension_ data(m_ connection, &xcb_xfixes_id); extension_ reply_t *) 0x0
1042 {
(gdb) l
1037 xcb_get_
1038 free(xcb_
1039 }
1040
1041 void QXcbConnection:
1042 {
1043 xcb_generic_error_t *error = 0;
1044 const xcb_query_
1045 xfixes_first_event = reply->first_event;
1046
(gdb) n
[Thread 0xb10b0460 (LWP 8635) exited]
1044 const xcb_query_
(gdb) p m_connection
$1 = (xcb_connection_t *) 0x1fc9b0
(gdb) p xcb_xfixes_id
$2 = {name = 0xb2433b28 "XFIXES", global_id = 2}
(gdb) n
1045 xfixes_first_event = reply->first_event;
(gdb) p reply
$3 = (const xcb_query_
Qt expects the first call to 'xcb_get_ extension_ data' to return a valid pointer, but in this case it's just returning NULL, breaking it up later on.