Re: cp -iu always prompts

[Evan Hunt]

> Indeed, without the -u, this behavior of cp -i is required by POSIX.  But
> since -u is a GNU extension, you are correct that it may be worth changing
> the behavior in this area to suppress the -i prompt if -u determines the
> dates imply no copy is needed.  Now all that is needed is for someone with
> enough time to write a patch.

Well, I have some time.  Patch below.

All it does is move the check for update mode ahead of the check for
interactivity.  So far I haven't thought of any adverse side-effects of
this change, and it passes all automated tests.

While I was in there, I noticed a similar bug with the -l/--link option:

        $ touch foo
        $ ln foo bar
        $ cp -li foo bar
        cp: overwrite `bar'?
        
There's no need at all to ask this question, since either answer will
result in the same outcome--bar will *not* be overwritten, and *will*
still be a hard link to foo.  So I moved that test to be before the
test for interactive mode, too.

Evan Hunt

----------------
*** copy.c.00   2006-12-27 21:31:38.000000000 -0800
--- copy.c      2006-12-27 21:48:58.000000000 -0800
***************
*** 1079,1084 ****
--- 1079,1131 ----
              return false;
            }
  
+ 
+         if (return_now)
+           return true;
+ 
+         if (!S_ISDIR (src_mode))
+           {
+             if (S_ISDIR (dst_sb.st_mode))
+               {
+                 if (x->move_mode && x->backup_type != no_backups)
+                   {
+                     /* Moving a non-directory onto an existing
+                        directory is ok only with --backup.  */
+                   }
+                 else
+                   {
+                     error (0, 0,
+                        _("cannot overwrite directory %s with non-directory"),
+                            quote (dst_name));
+                     return false;
+                   }
+               }
+ 
+             if (x->update)
+               {
+                 /* When preserving time stamps (but not moving within a file
+                    system), don't worry if the destination time stamp is
+                    less than the source merely because of time stamp
+                    truncation.  */
+                 int options = ((x->preserve_timestamps
+                                 && ! (x->move_mode
+                                       && dst_sb.st_dev == src_sb.st_dev))
+                                ? UTIMECMP_TRUNCATE_SOURCE
+                                : 0);
+ 
+                 if (0 <= utimecmp (dst_name, &dst_sb, &src_sb, options))
+                   {
+                     /* We're using --update and the destination is not older
+                        than the source, so do not copy or move.  Pretend the
+                        rename succeeded, so the caller (if it's mv) doesn't
+                        end up removing the source file.  */
+                     if (rename_succeeded)
+                       *rename_succeeded = true;
+                     return true;
+                   }
+               }
+           }
+ 
          /* When there is an existing destination file, we may end up
             returning early, and hence not copying/moving the file.
             This may be due to an interactive `negative' reply to the
***************
*** 1115,1123 ****
                return true;
            }
  
-         if (return_now)
-           return true;
- 
          if (!S_ISDIR (dst_sb.st_mode))
            {
              if (S_ISDIR (src_mode))
--- 1162,1167 ----
***************
*** 1154,1202 ****
                }
            }
  
-         if (!S_ISDIR (src_mode))
-           {
-             if (S_ISDIR (dst_sb.st_mode))
-               {
-                 if (x->move_mode && x->backup_type != no_backups)
-                   {
-                     /* Moving a non-directory onto an existing
-                        directory is ok only with --backup.  */
-                   }
-                 else
-                   {
-                     error (0, 0,
-                        _("cannot overwrite directory %s with non-directory"),
-                            quote (dst_name));
-                     return false;
-                   }
-               }
- 
-             if (x->update)
-               {
-                 /* When preserving time stamps (but not moving within a file
-                    system), don't worry if the destination time stamp is
-                    less than the source merely because of time stamp
-                    truncation.  */
-                 int options = ((x->preserve_timestamps
-                                 && ! (x->move_mode
-                                       && dst_sb.st_dev == src_sb.st_dev))
-                                ? UTIMECMP_TRUNCATE_SOURCE
-                                : 0);
- 
-                 if (0 <= utimecmp (dst_name, &dst_sb, &src_sb, options))
-                   {
-                     /* We're using --update and the destination is not older
-                        than the source, so do not copy or move.  Pretend the
-                        rename succeeded, so the caller (if it's mv) doesn't
-                        end up removing the source file.  */
-                     if (rename_succeeded)
-                       *rename_succeeded = true;
-                     return true;
-                   }
-               }
-           }
- 
          if (x->move_mode)
            {
              /* Don't allow user to move a directory onto a non-directory.  */
--- 1198,1203 ----