---(sudo_edit.c)
        /*
         * If we are unable to set the mtime on the temp file to the value
         * of the original file just make the stashed mtime match the temp
         * file's mtime.  It is better than nothing and we only use the info
         * to determine whether or not a file has been modified.
         */
        if (touch(tfd, NULL, &tf[i].omtim) == -1) {
            if (fstat(tfd, &sb) == 0) {
                tf[i].omtim.tv_sec = mtim_getsec(sb);
                tf[i].omtim.tv_nsec = mtim_getnsec(sb);
            }
            /* XXX - else error? */
        }
---

  if sudoedit is invoked on a filesystem who has different filetime resolution (eg one has nsec resolution one doesn't), as long as touch() succeeds, the result will be that the file is moved into place every time (unless it happens to line up on .000000 seconds in which case they'll naturally be equal).

  take the following from a running copy of sudoedit and its tmpfile, on a linux host where the tmp filesystem (ext3) does not offer nsec resolution, but the source filesystem (netapp nfs) does:

---
#linux 0918_02:27:36 $ stat myass /var/tmp/myass.XXYWIq4X                
  File: `myass'                                                                                                   
  Size: 0               Blocks: 0          IO Block: 65536  regular empty file        
Device: 15h/21d Inode: 3279889     Links: 1                                           
Access: (0644/-rw-r--r--)  Uid: (  645/    jrrs)   Gid: (  645/    jrrs)              
Access: 2009-09-18 02:23:28.325745000 -0400
Modify: 2009-09-18 02:23:28.325745000 -0400
Change: 2009-09-18 02:23:28.325745000 -0400                               
  File: `/var/tmp/myass.XXYWIq4X'                                         
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: 807h/2055d      Inode: 30          Links: 1
Access: (0600/-rw-------)  Uid: (  645/    jrrs)   Gid: (  645/    jrrs)
Access: 2009-09-18 02:27:34.000000000 -0400
Modify: 2009-09-18 02:23:28.000000000 -0400
Change: 2009-09-18 02:27:34.000000000 -0400
---