Crash printing character info TAB character

[Chong Yidong]

On latest trunk, GNU Emacs 24.0.90.17 (x86_64-unknown-linux-gnu, GTK+
Version 2.24.6):

emacs -Q
C-q TAB
C-b
C-u C-x =

Program received signal SIGSEGV, Segmentation fault.
0x00000000004f6345 in x_set_glyph_string_gc (s=0x7fffffffaf00) at xterm.c:1061
1061      PREPARE_FACE_FOR_DISPLAY (s->f, s->face);
(gdb) bt
#0  0x00000000004f6345 in x_set_glyph_string_gc (s=0x7fffffffaf00)
    at xterm.c:1061
#1  0x00000000004fa90e in x_draw_glyph_string (s=0x7fffffffaf00)
    at xterm.c:2685
#2  0x000000000046bd3a in draw_glyphs (w=0x1015ed0, x=225, row=0x152b880,
    area=TEXT_AREA, start=0, end=27, hl=DRAW_NORMAL_TEXT, overlaps=0)
    at xdisp.c:23002
#3  0x0000000000471e9c in x_write_glyphs (start=0x160bbd0, len=27)
    at xdisp.c:24636
#4  0x0000000000417c01 in update_text_area (w=0x1015ed0, vpos=12)
    at dispnew.c:3765
#5  0x0000000000418538 in update_window_line (w=0x1015ed0, vpos=12,
    mouse_face_overwritten_p=0x7fffffffb5a4) at dispnew.c:4006
#6  0x00000000004177ef in update_window (w=0x1015ed0, force_p=1)
    at dispnew.c:3625
#7  0x0000000000416e81 in update_window_tree (w=0x1015ed0, force_p=1)
    at dispnew.c:3326
#8  0x0000000000416e59 in update_window_tree (w=0x1030db0, force_p=1)
    at dispnew.c:3324
#9  0x0000000000416c27 in update_frame (f=0x100dbe0, force_p=1,
    inhibit_hairy_id_p=0) at dispnew.c:3253
...
(gdb) p s->face
$1 = (struct face *) 0x0