[Bug 1164783] [NEW] during manual partitioning, the size is off-by-one, this causes unexpected resizing

[codeslinger]

Public bug reported:

13.04 Beta1  UbuntuStudio


Run the Installer and choose "Something Else"

on the manual partitioning "Installation Type" screen, choose a partiton
and click the [Change] button.

a dialog will open with the current size of the partition and the
ability to change that size.

Bug: compare the size that you see in the dialog, to the size of the
partition as reported in the main window.  The size is off-by-one.  see
attached screenshot

This causes the partitioner to go into resize mode, even when you do not
intend to alter the size.

Furhtermore, even if you change the size in the dialog to be the same as
the size in the main window, it still enters resize mode when the dialog
is closed.  This may be due to a "value changed" flag, or this may be
due to the error induced by rounding sectors to the nearest megabyte.

Note: on this computer, the partitons are not track aligned.  this might
make a difference in this behavior.

Expected:  
1) There should not be an off-by-one error

2) The only proper way to decide if a resize is needed is to compare the
original value that was placed into the Change dialog, to the value that
was returned from the dialog.   This comparision must be preformed on
the numeric value so as to avoid getting confused by leading zeros and
space characters etc.  Only if the values are different should the
resize action be invoked.

Furthermore it may make sense to limit it to some minmum threshold, does
it really make sense to resize a partition by less than N megs?
Anything less than 100 megs is probably a mistake.

** Affects: ubiquity (Ubuntu)
     Importance: Undecided
         Status: New

** Attachment added: "screenshot - dialog with bad size off-by-one"
   https://bugs.launchpad.net/bugs/1164783/+attachment/3622039/+files/bad-size-circled.png

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to ubiquity in Ubuntu.
https://bugs.launchpad.net/bugs/1164783

Title:
  during manual partitioning, the size is off-by-one, this causes
  unexpected resizing

Status in “ubiquity” package in Ubuntu:
  New

Bug description:
  13.04 Beta1  UbuntuStudio

  
  Run the Installer and choose "Something Else"

  on the manual partitioning "Installation Type" screen, choose a
  partiton and click the [Change] button.

  a dialog will open with the current size of the partition and the
  ability to change that size.

  Bug: compare the size that you see in the dialog, to the size of the
  partition as reported in the main window.  The size is off-by-one.
  see attached screenshot

  This causes the partitioner to go into resize mode, even when you do
  not intend to alter the size.

  Furhtermore, even if you change the size in the dialog to be the same
  as the size in the main window, it still enters resize mode when the
  dialog is closed.  This may be due to a "value changed" flag, or this
  may be due to the error induced by rounding sectors to the nearest
  megabyte.

  Note: on this computer, the partitons are not track aligned.  this
  might make a difference in this behavior.

  Expected:  
  1) There should not be an off-by-one error

  2) The only proper way to decide if a resize is needed is to compare
  the original value that was placed into the Change dialog, to the
  value that was returned from the dialog.   This comparision must be
  preformed on the numeric value so as to avoid getting confused by
  leading zeros and space characters etc.  Only if the values are
  different should the resize action be invoked.

  Furthermore it may make sense to limit it to some minmum threshold,
  does it really make sense to resize a partition by less than N megs?
  Anything less than 100 megs is probably a mistake.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1164783/+subscriptions