Description of problem:

When performing a text install and choosing autopartition, manual partition acts
in a non-intuitive way.  If you select  "Fill all available space:" and deselect
the other partition size options, an error returns:

Invalid Entry for Partition Size
Must specify a value.

One would assume that if you are selecting an option to fill the partition with
all available space, it would not be necessary to define any sizing.

As it so happens, if you put a 1 in the "Size (MB)" field, it will accept that
and go forward, creating a partition which uses all available space.  Putting in
a 0 (zero) causes anaconda to crash.  See the follow-on bug report for the
traceback.

Version-Release number of selected component (if applicable):

RHEL 3
anaconda as ships with RHEL 3
diskdruid? as ships with RHEL 3

How reproducible:
Always.

Steps to Reproduce:
1. Start a text install of RHEL 3, choose autopartitioning
2. Manually tweak the offered partition, creating a new partition which takes up
all available space
3. Set the "Size (MB)" to 0 (zero) to crash, or to nothing to cause it to error
in an unexpected fashion.
    
Actual results:
Crash or apparent inability to set a dynamic partition creating size without
specifying a static vallue.

Expected results:
Nothing crashes or complains when the "Size (MB)" filed is filled with 0 or left
blank.

Additional info:

See follow-up traceback.