Comment 4 for bug 300310

Here is the full backtrace:

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7f827623b6e0 (LWP 8148)]
VidModeGetFirstModeline (scrnIndex=<value optimized out>, mode=0x7fff7e25b778, dotClock=0x7fff7e25b784)
    at ../../../../hw/xfree86/common/xf86VidMode.c:229
229 ../../../../hw/xfree86/common/xf86VidMode.c: No such file or directory.
        in ../../../../hw/xfree86/common/xf86VidMode.c
(gdb) backtrace full
#0 VidModeGetFirstModeline (scrnIndex=<value optimized out>, mode=0x7fff7e25b778,
    dotClock=0x7fff7e25b784) at ../../../../hw/xfree86/common/xf86VidMode.c:229
        pScrn = (ScrnInfoPtr) 0x25925b0
#1 0x0000000000485a32 in VidModeGetNumOfModes (scrnIndex=39526608)
    at ../../../../hw/xfree86/common/xf86VidMode.c:451
        mode = (pointer) 0x0
        dotClock = 0
        nummodes = 0
#2 0x00007f82738f5031 in ProcXF86VidModeGetAllModeLines (client=0x289ea60)
    at ../../../../../hw/xfree86/dixmods/extmod/xf86vmode.c:534
        rep = {type = 40 '(', pad1 = 69 'E', sequenceNumber = 126, length = 0, modecount = 4527588,
  pad2 = 0, pad3 = 0, pad4 = 0, pad5 = 42592864, pad6 = 0}
        mdinf = {dotclock = 0, hdisplay = 0, hsyncstart = 0, hsyncend = 0, htotal = 0, hskew = 0,
  vdisplay = 0, vsyncstart = 0, vsyncend = 0, vtotal = 0, pad1 = 16751, flags = 0, reserved1 = 0,
  reserved2 = 0, reserved3 = 39886816, privsize = 0}
        oldmdinf = {dotclock = 8275232, hdisplay = 0, hsyncstart = 0, hsyncend = 134, htotal = 0,
  vdisplay = 0, vsyncstart = 0, vsyncend = 30928, vtotal = 633, flags = 0, privsize = 5319427}
        mode = <value optimized out>
        modecount = <value optimized out>
        dotClock = <value optimized out>
        ver = 2
#3 0x000000000044d6e4 in Dispatch () at ../../dix/dispatch.c:454
        result = <value optimized out>
        client = (ClientPtr) 0x289ea60
        nready = 0
        start_tick = 460
#4 0x00000000004336fd in main (argc=8, argv=0x7fff7e25ba48, envp=<value optimized out>)
    at ../../dix/main.c:441
        i = 1
        error = 0
        xauthfile = <value optimized out>
        alwaysCheckForInput = {0, 1}