[rdiff-backup-users] rdiff-backup on Windows

[Josh Nisly]

Here are the first of the patches to the python code itself in order to 
run on Windows.

The fs_abilities.py changes are because we test many different file 
system operations in order to see if they are supported, and catch 
exceptions to see if they aren't. In the changed functions, the python 
functions being called simply don't exist on Windows, raising an 
attribute error. We just catch this like we catch IOError and OSError.

Python on Windows also doesn't have the getuid(), getguid(), etc. 
functions. What I've done is caught this case, and we simply act as if 
we are running as root (UID and GID of 0.) I think this is ok, at least 
in the short term, for the following reasons. First, most users are 
running their computer as administrator. This gives them read/write 
access to almost all the files on their computer. (Hard to believe with 
a unix background, but true.) Secondly, on restore, a typical user 
doesn't care (or even know) about things like file ownership, so 
restoring all files with the user running the process as the owner is fine.

I don't think this behavior is ideal, and would like to eventually try 
to come up with a way to determine it (probably with a C module), but I 
believe that it is much better to get a working port that most people 
can use and fix the problems with it, then work on perfecting permissions.

Thanks,
JoshN

--- rdiff_backup/fs_abilities.py        2008-01-03 09:36:48.000000000 -0600
+++ rdiff_backup/fs_abilities.py        2008-04-05 14:30:35.390625000 -0500
@@ -169,7 +169,7 @@
                try:
                        tmp_rp.chown(uid+1, gid+1) # just choose random uid/gid
                        tmp_rp.chown(0, 0)
-               except (IOError, OSError): self.ownership = 0
+               except (IOError, OSError, AttributeError): self.ownership = 0
                else: self.ownership = 1
                tmp_rp.delete()
 
@@ -184,7 +184,7 @@
                        hl_dest.hardlink(hl_source.path)
                        if hl_source.getinode() != hl_dest.getinode():
                                raise IOError(errno.EOPNOTSUPP, "Hard links 
don't compare")
-               except (IOError, OSError):
+               except (IOError, OSError, AttributeError):
                        if Globals.preserve_hardlinks != 0:
                                log.Log("Warning: hard linking not supported by 
filesystem "
                                                "at %s" % (self.root_rp.path,), 
3)
@@ -455,7 +455,7 @@
                sym_dest = dir_rp.append("symlinked_file2")
                try:
                        sym_dest.symlink(sym_source.path)
-               except (OSError):
+               except (OSError, AttributeError):
                        self.symlink_perms = 0
                else:
                        sym_dest.setdata()

--- rdiff_backup/Globals.py     2008-01-03 09:36:49.000000000 -0600
+++ rdiff_backup/Globals.py     2008-04-05 14:30:35.375000000 -0500
@@ -47,9 +47,14 @@
 
 # uid and gid of the owner of the rdiff-backup process.  This can
 # vary depending on the connection.
-process_uid = os.getuid()
-process_gid = os.getgid()
-process_groups = [process_gid] + os.getgroups()
+try:
+    process_uid = os.getuid()
+    process_gid = os.getgid()
+    process_groups = [process_gid] + os.getgroups()
+except AttributeError:
+    process_uid = 0
+    process_gid = 0
+    process_groups = [0]
 
 # If true, when copying attributes, also change target's uid/gid
 change_ownership = None