[Bug-ddrescue] Complete Only in ddrescue appears to not work as documented.

[Tim White]

I'm hoping I understand the -C (--complete-only) option properly.
I have a rescue that I am doing that I wish to limit to the current 
amount rescued, just filling in the areas that didn't rescue the first time.

Initial run as
$ ddrescue /dev/sdc /dev/null rescue.log
....
Current status
rescued:   211755 MB,  errsize:    108 kB,  current rate:   72744 kB/s
   ipos:   211755 MB,   errors:       2,    average rate:   69519 kB/s
   opos:   211755 MB,     time from last successful read:       0 s
^Cpying non-tried blocks...
Interrupted by user

I then add the -C option so that I can force it to rescue the parts from 
the 2 errors.
$ ddrescue -C /dev/sdc /dev/null rescue.log

Press Ctrl-C to interrupt
Initial status (read from logfile)
rescued:   211755 MB,  errsize:    108 kB,  errors:       2
Current status
rescued:   212003 MB,  errsize:    108 kB,  current rate:   73662 kB/s
   ipos:   212003 MB,   errors:       2,    average rate:   61980 kB/s
   opos:   212003 MB,     time from last successful read:       0 s

It just continues rescuing from the end of the logfile instead of 
limiting it to the log file blocks.

Thinking it may be because I'm using /dev/null as the output, I also 
changed it over to a file (which of course at this stage only used a few 
Mb instead of many Gb due to the holes in the file as it had already 
rescued the rest to /dev/null).

I expect the -C option to prevent it reading past the data already 
rescued (so 212003 MB now) and work at rescuing the remaining data 
between 0Mb and 212003 MB.

$ ddrescue -V
GNU ddrescue 1.11
Copyright (C) 2009 Antonio Diaz Diaz.

$ lsb_release -a
No LSB modules are available.
Distributor ID:    Ubuntu
Description:    Ubuntu 11.04
Release:    11.04
Codename:    natty

Thanks

Timothy White