file-name-all-completions

[Greg Hill]

platform:  GNU Emacs 21.2.2 (sparc-sun-solaris2.7, X toolkit)

This is a really wierd one that I hate to report because it will 
probably be impossible for you to even replicate it, let alone do 
anything about it.

I can only catch it happening once in thousands of tries.  Most 
likely it is not even truely an "Emacs bug," because it probably 
originates in the operating system, and for all I know there is no 
way that Emacs could possibly even detect that it has happened.  It 
might properly be called an "Emacs bug" if-and-only-if it can be 
shown that Emacs potentially _could_ have detected a file system 
error but failed to notice and report it.

The platform (described above) is getting its directory data from an 
NSF-mounted drive.  Once in a blue moon the directory listing 
returned by 'file-name-all-completions is incomplete.  The missing 
file names are always from what would have been the beginning of a 
complete list.  Below is the invocation of the function in question 
and the results returned as it was executed four time in succession 
in my *scratch* buffer.  (Getting two errors in a row like that was 
_really_ unusual.)  The first and last lists are correct.

  (file-name-all-completions "ecom" bom.BrdPin-dir)
  ("ecom-n" "ecom-m" "ecom-k" "ecom-j" "ecom-g" "ecom-f" "ecom-e" 
"ecom-d" "ecom-h" "ecom-c" "ecom-a")
  ("ecom-m" "ecom-k" "ecom-j" "ecom-g" "ecom-f" "ecom-e" "ecom-d" 
"ecom-h" "ecom-c" "ecom-a")
  ("ecom-g" "ecom-f" "ecom-e" "ecom-d" "ecom-h" "ecom-c" "ecom-a")
  ("ecom-n" "ecom-m" "ecom-k" "ecom-j" "ecom-g" "ecom-f" "ecom-e" 
"ecom-d" "ecom-h" "ecom-c" "ecom-a")

I'm not expecting you to be able to solve this problem.  However, I 
thought you might at least be interested in knowing about it, in case 
you can think of some way that the file system error could be 
detected and reported.

--Greg