Hi, I am getting a pretty reproducible bug in my own build of emacs-24.2.50.1 on osx-10.8.2 with the "lion fullscreen patch" from somewhere. Build info: git://git.savannah.gnu.org/emacs.git@fbfb2416 additional patch attached in fullscreen.patch config.log attached Steps to reproduce: 1. Install auto-complete-1.3.1 and git://github.com/brianjcj/auto-complete-clang 2. Visit a c++ file 3. Try completing some stuff 4. Segfaults after not too much messing around Backtrace: (gdb) bt #0 0x00007fff96242d46 in __kill () #1 0x000000010009f63e in fatal_error_backtrace (sig=6, backtrace_limit=6) at emacs.c:331 #2 0x00000001000bc5b3 in emacs_abort () at sysdep.c:1830 #3 0x000000010018c73d in ns_term_shutdown (sig=) at nsterm.m:4229 #4 0x000000010009f5f1 in fatal_error_backtrace (sig=11, backtrace_limit=10) at emacs.c:314 #5 0x00000001000a1cde in handle_fatal_signal (sig=) at emacs.c:287 #6 0x00000001000bc80d in handle_on_main_thread (sig=11, handler=0x1000a1cd0 ) at sysdep.c:1493 #7 #8 0x0000000100087491 in char_table_ref () at chartab.c:233 #9 0x000000010016fadf in composition_compute_stop_pos (cmp_it=0x7fff5fbf2770, charpos=4195335, bytepos=5, endpos=4300718816, string=140734799751024) at composite.c:1053 #10 0x000000010002e701 in compute_stop_pos (it=0x7fff5fbf4c40) at xdisp.c:3393 #11 0x000000010002fdcb in next_element_from_string (it=0x7fff5fbf43d8) at xdisp.c:7525 #12 0x00000001000318f2 in get_next_display_element (it=0x7fff5fbf43d8) at xdisp.c:6568 #13 0x0000000100039f06 in display_line (it=0x7fff5fbf43d8) at xdisp.c:19382 #14 0x00000001000410cf in try_window (window=4346955808, flags=1606373632) at xdisp.c:16285 #15 0x000000010004a5b6 in redisplay_window (window=140734799758296, just_this_one_p=1606393984) at xdisp.c:15811 #16 0x0000000100035d86 in redisplay_window_0 (window=140734799758296) at xdisp.c:13879 #17 0x000000010011b030 in internal_condition_case_1 (bfun=0x100035d60 , arg=140734799758296, handlers=4320156886, hfun=0x100016250 ) at eval.c:1346 #18 0x0000000100035d3c in redisplay_windows (window=140734799758296) at xdisp.c:13859 #19 0x00000001000422ad in redisplay_internal () at xdisp.c:13439 #20 0x0000000100042b37 in redisplay_preserve_echo_area (from_where=51992685) at xdisp.c:13695 #21 0x00000001000aaf39 in detect_input_pending_run_timers (do_display=1) at keyboard.c:10361 #22 0x000000010015dbed in wait_reading_process_output (time_limit=140734799790240, nsecs=1606402208, read_kbd=1606402208, do_display=1606402208, wait_for_cell=140734799790240, wait_proc=0x7fff5fbfc0a0, just_wait_proc=0) at process.c:4768 #23 0x00000001000056c5 in sit_for (timeout=28, do_display=1, reading=true) at dispnew.c:5977 #24 0x00000001000ae6e8 in read_char (commandflag=1606402928, nmaps=140734799790960, maps=0x7fff5fbfc370, prev_event=1, used_mouse_menu=0x7fff5fbfc370, end_time=0x7fff5fbfc370) at keyboard.c:2707 #25 0x00000001000b26b1 in read_key_sequence () at keyboard.c:2838 #26 0x00000001000b4148 in command_loop_1 () at keyboard.c:1487 #27 0x000000010011b186 in internal_condition_case (bfun=0x1000b2d10 , handlers=4320212282, hfun=0x1000b41d0 ) at eval.c:1308 #28 0x00000001000b2cee in command_loop_2 (ignore=140734799791752) at keyboard.c:1182 #29 0x000000010011b282 in internal_catch (tag=140734799791752, func=0x1000b2cb0 , arg=140734799791752) at eval.c:1069 #30 0x00000001000b4760 in command_loop [inlined] () at /Users/leif/git/emacs/src/keyboard.c:1161 #31 0x00000001000b4760 in recursive_edit_1 () at keyboard.c:782 #32 0x00000001000a4ead in Frecursive_edit () at keyboard.c:846 #33 0x00000001000a1c2d in main (argc=25241098, argv=0x7fff5fbfcc70) at emacs.c:1655 (gdb) thread apply all bt Thread 5 (core thread 4): #0 0x00007fff96243322 in select$DARWIN_EXTSN () #1 0x000000010018876b in -[EmacsApp fd_handler:] (self=0x5, _cmd=0x100f09b00, unused=0x0) at nsterm.m:4570 #2 0x00007fff9750a612 in __NSThread__main__ () #3 0x00007fff930d4742 in _pthread_start () #4 0x00007fff930c1181 in thread_start () Thread 4 (core thread 3): #0 0x00007fff962436d6 in __workq_kernreturn () #1 0x00007fff930d6eec in _pthread_workq_return () #2 0x00007fff930d6cb3 in _pthread_wqthread () #3 0x00007fff930c1171 in start_wqthread () Thread 3 (core thread 2): #0 0x00007fff96243d16 in kevent () #1 0x00007fff8c571dea in _dispatch_mgr_invoke () #2 0x00007fff8c5719ee in _dispatch_mgr_thread () Thread 2 (core thread 1): #0 0x00007fff962436d6 in __workq_kernreturn () #1 0x00007fff930d6eec in _pthread_workq_return () #2 0x00007fff930d6cb3 in _pthread_wqthread () #3 0x00007fff930c1171 in start_wqthread () Thread 1 (core thread 0): #0 0x00007fff96242d46 in __kill () #1 0x000000010009f63e in fatal_error_backtrace (sig=6, backtrace_limit=6) at emacs.c:331 #2 0x00000001000bc5b3 in emacs_abort () at sysdep.c:1830 #3 0x000000010018c73d in ns_term_shutdown (sig=) at nsterm.m:4229 #4 0x000000010009f5f1 in fatal_error_backtrace (sig=11, backtrace_limit=10) at emacs.c:314 #5 0x00000001000a1cde in handle_fatal_signal (sig=) at emacs.c:287 #6 0x00000001000bc80d in handle_on_main_thread (sig=11, handler=0x1000a1cd0 ) at sysdep.c:1493 #7 #8 0x0000000100087491 in char_table_ref () at chartab.c:233 #9 0x000000010016fadf in composition_compute_stop_pos (cmp_it=0x7fff5fbf2770, charpos=4195335, bytepos=5, endpos=4300718816, string=140734799751024) at composite.c:1053 #10 0x000000010002e701 in compute_stop_pos (it=0x7fff5fbf4c40) at xdisp.c:3393 #11 0x000000010002fdcb in next_element_from_string (it=0x7fff5fbf43d8) at xdisp.c:7525 #12 0x00000001000318f2 in get_next_display_element (it=0x7fff5fbf43d8) at xdisp.c:6568 #13 0x0000000100039f06 in display_line (it=0x7fff5fbf43d8) at xdisp.c:19382 #14 0x00000001000410cf in try_window (window=4346955808, flags=1606373632) at xdisp.c:16285 #15 0x000000010004a5b6 in redisplay_window (window=140734799758296, just_this_one_p=1606393984) at xdisp.c:15811 #16 0x0000000100035d86 in redisplay_window_0 (window=140734799758296) at xdisp.c:13879 #17 0x000000010011b030 in internal_condition_case_1 (bfun=0x100035d60 , arg=140734799758296, handlers=4320156886, hfun=0x100016250 ) at eval.c:1346 #18 0x0000000100035d3c in redisplay_windows (window=140734799758296) at xdisp.c:13859 #19 0x00000001000422ad in redisplay_internal () at xdisp.c:13439 #20 0x0000000100042b37 in redisplay_preserve_echo_area (from_where=51992685) at xdisp.c:13695 #21 0x00000001000aaf39 in detect_input_pending_run_timers (do_display=1) at keyboard.c:10361 #22 0x000000010015dbed in wait_reading_process_output (time_limit=140734799790240, nsecs=1606402208, read_kbd=1606402208, do_display=1606402208, wait_for_cell=140734799790240, wait_proc=0x7fff5fbfc0a0, just_wait_proc=0) at process.c:4768 #23 0x00000001000056c5 in sit_for (timeout=28, do_display=1, reading=true) at dispnew.c:5977 #24 0x00000001000ae6e8 in read_char (commandflag=1606402928, nmaps=140734799790960, maps=0x7fff5fbfc370, prev_event=1, used_mouse_menu=0x7fff5fbfc370, end_time=0x7fff5fbfc370) at keyboard.c:2707 #25 0x00000001000b26b1 in read_key_sequence () at keyboard.c:2838 #26 0x00000001000b4148 in command_loop_1 () at keyboard.c:1487 #27 0x000000010011b186 in internal_condition_case (bfun=0x1000b2d10 , handlers=4320212282, hfun=0x1000b41d0 ) at eval.c:1308 #28 0x00000001000b2cee in command_loop_2 (ignore=140734799791752) at keyboard.c:1182 #29 0x000000010011b282 in internal_catch (tag=140734799791752, func=0x1000b2cb0 , arg=140734799791752) at eval.c:1069 #30 0x00000001000b4760 in command_loop [inlined] () at /Users/leif/git/emacs/src/keyboard.c:1161 #31 0x00000001000b4760 in recursive_edit_1 () at keyboard.c:782 #32 0x00000001000a4ead in Frecursive_edit () at keyboard.c:846 #33 0x00000001000a1c2d in main (argc=25241098, argv=0x7fff5fbfcc70) at emacs.c:1655 Let me know if there's anything else I can do to help. I'm not familiar with emacs code but I'm handy with gdb. I'm uploading the corefile to my server, it's gonna be maybe a half an hour (it's ~120MB bzipped), when it's done you can: wget 'http://leifwalsh.com/emacs24-osx10.8-segfault-auto-complete-clang.core.bz2' -O- | bunzip2 -c >core.34598 -- Cheers, Leif