Description of problem:
I planned to install test F18 beta on my allocated empty partition in my hard disk (the other non-empty partition is windows 7). In the customzing partition section I merely click on my ntfs partition to confirm that is not overwritten, no changes are performed. This crash error immediately popped out and asked me to file a bug.

Version-Release number of selected component:
anaconda-18.12

Additional info:
libreport version: 2.0.14
cmdline:        /usr/bin/python  /sbin/anaconda
kernel:         3.6.0-1.fc18.x86_64

description:
:The following was filed automatically by anaconda:
:anaconda 18.12 exception report
:Traceback (most recent call first):
:  File "/usr/lib64/python2.7/site-packages/parted/disk.py", line 309, in setPartitionGeometry
:    start, end)
:  File "/usr/lib64/python2.7/site-packages/parted/decorators.py", line 32, in new
:    ret = fn(*args, **kwds)
:  File "/usr/lib64/python2.7/site-packages/pyanaconda/storage/devices.py", line 1230, in _setTargetSize
:    start=geometry.start, end=geometry.end)
:  File "/usr/lib64/python2.7/site-packages/pyanaconda/storage/devices.py", line 599, in <lambda>
:    lambda s, v: s._setTargetSize(v),
:  File "/usr/lib64/python2.7/site-packages/pyanaconda/storage/deviceaction.py", line 367, in __init__
:    self.device.targetSize = newsize
:  File "/usr/lib64/python2.7/site-packages/pyanaconda/storage/__init__.py", line 1251, in resizeDevice
:    self.devicetree.registerAction(action_class(device, new_size))
:  File "/usr/lib64/python2.7/site-packages/pyanaconda/ui/gui/spokes/custom.py", line 955, in _save_right_side
:    self.__storage.resizeDevice(device, size)
:  File "/usr/lib64/python2.7/site-packages/pyanaconda/ui/gui/spokes/custom.py", line 1552, in on_page_clicked
:    self._save_right_side(self._current_selector)
:  File "/usr/lib64/python2.7/site-packages/pyanaconda/ui/gui/spokes/lib/accordion.py", line 115, in _onExpanded
:    cb(obj.get_child())
:PartitionException: Can't have overlapping partitions.