Crash of Xorg Server after xrandr --setprovideroutputsource

I was using Ubuntu 14.04 amd64 and had the same problem. Currently Slackware 14.1 64 bit.

I have:

bash-4.2$ uname -a
Linux random 3.10.17 #2 SMP Wed Oct 23 16:34:38 CDT 2013 x86_64 Intel® Pentium® CPU B960 @ 2.20GHz GenuineIntel GNU/Linux

[ installed ] - xorg-cf-files-1.0.4-noarch-1
[ installed ] - xorg-docs-1.7-noarch-1
[ installed ] - xorg-server-1.14.3-x86_64-2
[ installed ] - xorg-server-xephyr-1.14.3-x86_64-2
[ installed ] - xorg-server-xnest-1.14.3-x86_64-2
[ installed ] - xorg-server-xvfb-1.14.3-x86_64-2
[ installed ] - xorg-sgml-doctools-1.11-x86_64-1

This xorg.conf:
xorg.conf 749 B!88kzVILZ!0jAp1FiCIHIQj7gDtl_oNM3ofLKLF9JVwJqNR2sWLRI
this hardware:
lspci 4 KB!csMXQZLb!5Xh4qm7uz4XRRBwztPmFHXYEM1e7d6SJNFPSSGxXN7w

these providers (before crash):
bash-4.2$ cat listProviders.log
Providers: number : 2
Provider 0: id: 0x2b0 cap: 0x1, Source Output crtcs: 0 outputs: 0 associated providers: 0 name:NVIDIA-0
Provider 1: id: 0x45 cap: 0x2, Sink Output crtcs: 2 outputs: 4 associated providers: 0 name:modesetting

this configuration of i915:
lsmod | grep -i -e nvidia -e fb -e nouvea
nvidia 10476730 0
drm 229054 3 i915,drm_kms_helper,nvidia
i2c_core 20936 8 drm,i915,i2c_i801,i2c_dev,drm_kms_helper,i2c_algo_bit,nvidia,videodev
modinfo -p i915 | grep modesetting
modeset:Use kernel modesetting [KMS] (0=DRM_I915_KMS from .config, 1=on, -1=force vga console preference [default]) (int)
cat /sys/module/i915/parameters/modeset

xorg log before crash (command xrandr --setprovideroutputsource modesetting NVIDIA-0)
beforeXrandr.log 31 KB!o18z3JqR!grjZE_ZFvPMAgZMaox-1xlSVVd0qT6QmGl7UopsDyOs

xorg log after crash:
AfterXrandr.log 33 KB!851QGQCZ!XQ27gomMS_G5x1Zc3_G16cTkcUW1e2hD5s8G5h4txZc

dmesg.log 71 KB!VpMiHbJL!1dQ4QP01PihTQeEqd131Zp_aobvZOF4Wh7HtGdGOEj8

and logs from yours script
BeforeNvidia-bug-report.log.gz 63 KB!thNkABRA!gag9Kr2p7QnJn6JVFd2cmiSC2qoKMriQlmJ0eCKBNBw
AfterNvidia-bug-report.log.gz 63 KB!U0Mlzahb!eLkZjY0TjgxKATE5MsuBntiqDUweejzaBZH7rlsSEPc

What I did?
I installed Slackware. If there is no xorg.conf everything is rendered on Intel GPU and worked fine (and is working still). I installed nvidia driver. I added to blacklist module nouveau. Changed options for i915 module to enable modesetting. nvidiafb was blacklisted before:
bash-4.2$ grep -i fb /lib/modprobe.d/* | grep -i nvidia
/lib/modprobe.d/framebuffers.conf:blacklist nvidiafb
Added to environment variable DISPLAY:
bash-4.2$ cat .bash_profile
DISPLAY=":0"; export DISPLAY
Restarted PC.
Logged in text mode.
startx &
there is blank screen so I xrandr --setprovideroutputsource modesetting NVIDIA-0
and xorg server crashed.