Re: gnulib support for st_birthtime (second revision of patch)

[Bruno Haible]

On AIX 5.1, with gnulib as of today (29 March) the test-stat-time test fails.
More precisely, on a 'jfs2' file system, the test fails in the third ASSERT
of test_mtime. I get these time stamps:

$ stat t-stt-stamp1
  File: `t-stt-stamp1'
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: a0007h/655367d  Inode: 218         Links: 1
Access: (0500/-r-x------)  Uid: (  299/  haible)   Gid: (  430/    user)
Access: 2007-03-29 16:55:21.1555657784 +0100
Modify: 2007-03-29 16:55:21.1555657784 +0100
Change: 2007-03-29 16:55:21.1555657784 +0100
$ stat t-stt-stamp2
  File: `t-stt-stamp2'
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: a0007h/655367d  Inode: 822         Links: 1
Access: (0500/-r-x------)  Uid: (  299/  haible)   Gid: (  430/    user)
Access: 2007-03-29 16:55:25.1186180304 +0100
Modify: 2007-03-29 16:55:25.1186180304 +0100
Change: 2007-03-29 16:55:25.1186180304 +0100
$ stat t-stt-stamp3
  File: `t-stt-stamp3'
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: a0007h/655367d  Inode: 886         Links: 1
Access: (0500/-r-x------)  Uid: (  299/  haible)   Gid: (  430/    user)
Access: 2007-03-29 16:55:29.-1317180880 
Modify: 2007-03-29 16:55:29.-1317180880 
Change: 2007-03-29 16:55:29.-1317180880 
$ stat t-stt-renamed
  File: `t-stt-renamed'
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: a0007h/655367d  Inode: 219         Links: 1
Access: (0500/-r-x------)  Uid: (  299/  haible)   Gid: (  430/    user)
Access: 2007-03-29 16:55:23.-562647104 
Modify: 2007-03-29 16:55:23.-562647104 
Change: 2007-03-29 16:55:23.-562647104 

As you can see, the ctime has not been modified by the "mv" command.
"Change" and "Modify" times appear to be always the same on this file system, 
no matter what I do.

I can see two ways to fix the test:
- Turn this ASSERT into an 'if' that does appropriate action if not fulfilled.
- Immediately after renaming the file, write something into it, so that also
  on this weird filesystem the ctime is bumped.

Bruno