Bug 502291

I had an unaligned partition (in my case i had first sector 2048 and last sector 1953525134) and wanted to align it by resizing it.
In the advanced settings, the "Align" checkbox is selected, but the value of the end of the partition was not correct for creating an aligned partition (it was the original value of the current partition, unchanged).
After deselecting and selecting the alignment checkbox, the value changed to another one (from 1953525134 to 1953523711), which would have lead to an aligned partition

STEPS TO REPRODUCE
1. find an unaligned partition 
2. click on resize
3. open the advanced settings
4. verify that checkbox aligned is selected, but the value in the dialog would lead to an unaligned partition

OBSERVED RESULT
see description

EXPECTED RESULT
The UI seems to be in an inconsistent state.
I guess that the best way to solve it would be to show a warning that the partition is not aligned, and explain that either the user deselects the checkbox, or the last sector will be changed accordingly.
I do not know (because I did not have the patience to test it) what would have happened if I did not toggle the checkbox twice.
Would it have tried to create an unaligned partition of the indicated size, or would it have created an aligned partition of another size?