Re: completion bug: treats substitution of unset parameter as empty string

[Peter Stephenson <pws@csr.com>]

On Thu, 10 Sep 2009 10:30:42 -0400
Greg Klanderman <gak@klanderman.net> wrote:
> Here's a patch to fix the originally reported problem - that
> _path_files incorrectly treats a parameter expansion of an
> unset parameter as the empty string, i.e. that
> 
> % ls $foobar/ <tab>
> 
> lists completions under '/'.

That's fine, however I think (belatedly answering your other question)
that, since we don't need to backport this anywhere, using an anonymous
function would be neater---so we're not relying on the value of "nounset"
outside.  In practice if it were set outside all hell would break loose, so
this is pretty pernickety, but perhaps it's a useful precedent.

Index: Completion/Unix/Type/_path_files
===================================================================
RCS file: /cvsroot/zsh/zsh/Completion/Unix/Type/_path_files,v
retrieving revision 1.47
diff -u -r1.47 _path_files
--- Completion/Unix/Type/_path_files	5 Aug 2009 00:46:45 -0000	1.47
+++ Completion/Unix/Type/_path_files	10 Sep 2009 14:36:56 -0000
@@ -247,7 +247,11 @@
   # meant as a partial path.
 
   linepath="${(M)pre##*\$[^/]##/}"
-  eval 'realpath=${(e)~linepath}' 2>/dev/null
+  function {
+    # do not treat an unset parameter expansion as the empty string
+    setopt localoptions nounset
+    eval 'realpath=${(e)~linepath}' 2>/dev/null
+  }
   [[ -z "$realpath" || "$realpath" = "$linepath" ]] && return 1
   pre="${pre#${linepath}}"
   i='[^/]'

-- 
Peter Stephenson <pws@csr.com>            Software Engineer
Tel: +44 (0)1223 692070                   Cambridge Silicon Radio Limited
Churchill House, Cambridge Business Park, Cowley Road, Cambridge, CB4 0WZ, UK


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