[ET Trac] [Einstein Toolkit] #453: Formaline deletes files if lib and src are symlinks

[Einstein Toolkit]

#453: Formaline deletes files if lib and src are symlinks
----------------------------+-----------------------------------------------
  Reporter:  barry.wardell  |       Owner:     
      Type:  defect         |      Status:  new
  Priority:  major          |   Milestone:     
 Component:  Cactus         |     Version:     
Resolution:                 |    Keywords:     
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Comment (by barry.wardell):

 Replying to [comment:7 eschnett]:
 > Yes, that is the idea. The patch as stop-gap measure, and then trying to
 understand the real cause of the problem and correcting git-add-thorn.pl.

 OK, I have committed this patch anyway.

 > I do not think that Mac OS allows hard links to directories for regular
 users. With these, one can create directory structures that are not trees,
 which would break many Unix expectations; in particular, one can create
 directory structures disconnected from the root directory and hence
 unreachable. Root can call the "link" syscall (maybe even from the "ln"
 command, possibly with a special option) to do this, but it's highly
 discouraged.

 Nevertheless, this is the case:

 $ stat -f %i dir1/dir2
 7846166
 $ stat -f %i dir4
 7846166


 Note that in contrast to my above test case, the following does not have
 the same problem:

 mkdir dir1
 touch dir1/file
 ln -s dir1 dir3
 perl -e 'link dir3, dir4'

 In this case, dir4 is not created. To me this seems like an OS/perl bug to
 me. Would the best think to do be to add an explicit check that the source
 is not a symlink or directory before it does the link command?

 Replying to [comment:8 rhaas]:
 > find's -L option recurses into symbolic links and is required by POSIX.
 One can turn it off again with the -H switch eg. for '-L ! -type d -H' or
 just put it at the beginning of the whole find line.

 I was going to originally suggest this as alternative solution. The only
 reason I didn't was that with the patch as-is it only affects this
 particular case, whereas I was worried that adding -L could have some
 other unrelated effects (either good or bad).

-- 
Ticket URL: <https://trac.einsteintoolkit.org/ticket/453#comment:9>
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