[rdiff-backup-users] Incremental chokes on read-only files (windows)

[Veder]

Hello,

Coming from a windows world we are now deploying
more and more linux servers and we were looking for
a solid cross-platform open-source backup solution.
Rdiff-backup looks just fine for that (impressive
in features, smart design). Especially the single-exe
in Windows is a plus compared with other cross-platform
products, avoiding to set up cygwin stuff.

However I ran into a problem when testing on windows
(XP and W2K3). rdiff-backup crashes when a read-only
file is backed up and in a subsequent run needs to
be included as incremented because of a file change.
Rdiff-backup seems to copy the R-attribute but appears
to be unable to remove it (or force-write) before
handling the increment-stuff. As a result the whole
backup is aborted.

Example output (where e: is the target drive):
  Exception '[Error 5] Access is denied: 'e:/rdiff.up/license.txt'
    ' raised of class '<type 'exceptions.WindowsError'>':
  File "rdiff_backup\Main.pyc", line 304, in error_check_Main
  File "rdiff_backup\Main.pyc", line 324, in Main
  File "rdiff_backup\Main.pyc", line 280, in take_action
  File "rdiff_backup\Main.pyc", line 343, in Backup
  File "rdiff_backup\backup.pyc", line 51, in Mirror_and_increment
  File "rdiff_backup\connection.pyc", line 450, in __call__
  File "rdiff_backup\connection.pyc", line 370, in reval

  Traceback (most recent call last):
  File "rdiff-backup", line 30, in <module>
  File "rdiff_backup\Main.pyc", line 304, in error_check_Main
  File "rdiff_backup\Main.pyc", line 324, in Main
  File "rdiff_backup\Main.pyc", line 280, in take_action
  File "rdiff_backup\Main.pyc", line 343, in Backup
  File "rdiff_backup\backup.pyc", line 51, in Mirror_and_increment
  File "rdiff_backup\connection.pyc", line 450, in __call__
  File "rdiff_backup\connection.pyc", line 370, in reval
  WindowsError: [Error 5] Access is denied: 'e:/rdiff.up/license.txt'


Real life example: Make a backup of a windows system
disk (preferably of a shadow copy of it) and then
modify c:\boot.ini (which is read only) and do another
backup. Rdiff-backup halts on incrementing c:\boot.ini.


Best regards,

Erwin