-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 According to Jim Meyering on 9/24/2009 12:29 AM: > bool same = false; > ... > same = SAME_INODE (source_dir_stats, dest_dir_stats); > if (same < 0) > same = (identical_basenames > && strcmp (source_basename, dest_basename) == 0);
As written, it wouldn't have worked, anyways. The idea is that "./file" and "/path/to/file" can be the same name, so we need more than a strcmp of the dirnames. Rather, it needs a strcmp of the canonicalized names. And since mingw doesn't have working canonicalize_file_name yet, it probably even means using getcwd/chdir(dirname)/getcwd/chdir(cwd) twice to determine the two names to compare. > > Your new test, "same < 0" will never be true when > compiled on a system with proper "bool" support. I missed that too. All the more reason that I reverted the patch. > Apparently, since your testing did not expose this flaw, > no tested use of same_name requires the new semantics of SAME_INODE. Correct - on mingw, I had tested the use of SAME_INODE, but not of same_name (it made a difference as to whether at_func2 mistakenly assumed two fds pointed to the same directory). Fortunately, on every other platform, SAME_INODE is still 0 or 1 (mingw is the only platform where st_ino is always 0, and therefore SAME_INODE was returning 1 even when it should have returned 0, leading to the tri-state proposal in the first place). I suppose that for mingw, I could also beef up SAME_INODE to return 0 instead of -1 if other reliable fields in st_ino, such as st_ctim or st_size, differ. (Note that on mingw, st_ctim is mistakenly the file creation time, corresponding to birthtime in BSD stat, rather than the last metadata change time as per POSIX, but it still serves as a reliable indicator of different files). > If the tri-state test is required in only a few places, > how about using a new macro, say SAME_INODE_TRISTATE, > in just those few places? There's two categories of clients of SAME_INODE - those that want to do something if the files are provably the same (any where I changed to SAME_INODE()==1), but which behave correctly if the files are different or indeterminate; and those that want to do something if the files are provably different, but which behave correctly if the files are the same or indeterminate. If SAME_INODE can be reached on mingw, then a decision about what to do in the indeterminate case is necessary, even if we can reduce the indeterminate result. - -- Don't work too hard, make some time for fun as well! Eric Blake e...@byu.net -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (Cygwin) Comment: Public key at home.comcast.net/~ericblake/eblake.gpg Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkq7Y6IACgkQ84KuGfSFAYD41gCcD3S6M/dD1jpXtlZ1TvPH5uba Q28AnA89dpmjlurco7jTDK9I4QesuP3Q =9RWr -----END PGP SIGNATURE-----
