Crashes in "C-h h"

[Eli Zaretskii]

I'm getting crashes in "C-h h", they are caused by some commit between
e51f328 and cb182ce.  I suspect f59a3f3 and/or 4893a09.  The backtrace
is below.

Does anyone else see this, in particular on X?

  lisp.h:1198: Emacs fatal error: assertion failed: FIXNUMP (a)

  Thread 1 hit Breakpoint 1, terminate_due_to_signal (sig=22,
      backtrace_limit=2147483647) at emacs.c:377
  377       signal (sig, SIG_DFL);
  (gdb) bt
  #0  terminate_due_to_signal (sig=22, backtrace_limit=2147483647)
      at emacs.c:377
  #1  0x011ff850 in die (msg=0x16f14a8 <PSEUDOVECTOR_FLAG+4> "FIXNUMP (a)",
      file=0x16f1478 <Qzlib+8> "lisp.h", line=1198) at alloc.c:7194
  #2  0x011467ac in XFIXNUM (a=XIL(0)) at lisp.h:1198
  #3  0x0135a8ea in fontset_find_font (fontset=XIL(0xa000000006a97b18), c=1047,
      face=0x68dc4f8, charset_id=15, fallback=false) at fontset.c:578
  #4  0x0135b689 in fontset_font (fontset=XIL(0xa000000006a94248), c=1047,
      face=0x68dc4f8, id=15) at fontset.c:773
  #5  0x0135c617 in face_for_char (f=0x6894338, face=0x68dc4f8, c=1047,
      pos=278, object=XIL(0)) at fontset.c:987
  #6  0x0114b5d5 in FACE_FOR_CHAR (f=0x6894338, face=0x68dc4f8, character=1047,
      pos=278, object=XIL(0)) at dispextern.h:1869
  #7  0x0104884e in get_next_display_element (it=0x82b660) at xdisp.c:7425
  #8  0x01078c76 in display_line (it=0x82b660, cursor_vpos=3) at xdisp.c:21830
  #9  0x0106b92e in try_window (window=XIL(0xa0000000068c6aa8), pos=...,
      flags=1) at xdisp.c:17884
  #10 0x01068a9e in redisplay_window (window=XIL(0xa0000000068c6aa8),
      just_this_one_p=false) at xdisp.c:17332
  #11 0x01060bd3 in redisplay_window_0 (window=XIL(0xa0000000068c6aa8))
      at xdisp.c:15057
  #12 0x012379da in internal_condition_case_1 (
      bfun=0x1060b78 <redisplay_window_0>, arg=XIL(0xa0000000068c6aa8),
      handlers=XIL(0xc0000000058cfe48), hfun=0x1060b35 <redisplay_window_error>)
      at eval.c:1376
  #13 0x01060af8 in redisplay_windows (window=XIL(0xa0000000068c6aa8))
      at xdisp.c:15037
  #14 0x0105f241 in redisplay_internal () at xdisp.c:14520
  #15 0x0105c673 in redisplay () at xdisp.c:13747
  #16 0x0115949a in read_char (commandflag=1, map=XIL(0xc000000006924650),
      prev_event=XIL(0), used_mouse_menu=0x82f47f, end_time=0x0)
      at keyboard.c:2474
  #17 0x0116f73f in read_key_sequence (keybuf=0x82f780, prompt=XIL(0),
      dont_downcase_last=false, can_return_switch_frame=true,
      fix_current_buffer=true, prevent_redisplay=false) at keyboard.c:9125
  #18 0x01155180 in command_loop_1 () at keyboard.c:1348
  #19 0x012378f0 in internal_condition_case (bfun=0x1154a7b <command_loop_1>,
      handlers=XIL(0x5430), hfun=0x1153d24 <cmd_error>) at eval.c:1352
  #20 0x01154527 in command_loop_2 (ignore=XIL(0)) at keyboard.c:1091
  #21 0x01236abb in internal_catch (tag=XIL(0xdcb0),
      func=0x11544eb <command_loop_2>, arg=XIL(0)) at eval.c:1113
  #22 0x011544a6 in command_loop () at keyboard.c:1070
  #23 0x011537ac in recursive_edit_1 () at keyboard.c:714
  #24 0x01153a22 in Frecursive_edit () at keyboard.c:786
  #25 0x011512a7 in main (argc=2, argv=0xa42828) at emacs.c:2103

  Lisp Backtrace:
  "redisplay_internal (C function)" (0x0)