[Tracker] crashes in HeaderView::ModelChanged

[luroh]

hrev53404, gcc2. Possibly similar to ticket:15302

Create an empty text file, bring up its InfoWindow and press Alt-o

state: Exception (Segment violation)

Frame		IP			Function Name
-----------------------------------------------
0x713b4af0	0x27b9864	HeaderView::ModelChanged(BPrivate::Model*, BMessage*) + 0x18 
	Disassembly:
		HeaderView::ModelChanged(BPrivate::Model*, BMessage*):
		0x027b984c:               55  push %ebp
		0x027b984d:             89e5  mov %esp, %ebp
		0x027b984f:           83ec0c  sub $0xc, %esp
		0x027b9852:               57  push %edi
		0x027b9853:               56  push %esi
		0x027b9854:               53  push %ebx
		0x027b9855:       e800000000  call 0x27b985a
		0x027b985a:               5b  pop %ebx
		0x027b985b:     81c3424e0f00  add $0xf4e42, %ebx
		0x027b9861:           8b5508  mov 0x8(%ebp), %edx
		0x027b9864:     8b82dc000000  mov 0xdc(%edx), %eax <--

	Frame memory:
		[0x713b4ad0]  .........$...J;q   9c e6 8a 02 00 0f fc 00 a0 24 89 0e f4 4a 3b 71
		[0x713b4ae0]  ........xM;q.`|.   9c e6 8a 02 00 0f fc 00 78 4d 3b 71 80 60 7c 02
0x713b4d80	0x27c607b	BPrivate::BInfoWindow::MessageReceived(BMessage*) + 0xca7 
0x713b4db0	0x1f4444d	BLooper::DispatchMessage(BMessage*, BHandler*) + 0x59 
0x713b4fb0	0x202e730	BWindow::DispatchMessage(BMessage*, BHandler*) + 0x18a0 
0x713b5010	0x2032e54	BWindow::task_looper() + 0x2d0 
0x713b5040	0x1f45931	BLooper::_task0_(void*) + 0x3d 
0x713b5068	0xb450cb	thread_entry + 0x27 
00000000	0x61faf258	commpage_thread_exit + 0

[pulkomandy]

Indeed duplicate of #15302, for which a fix is pending review on Gerrit already.