Subject: Failed process substitution on x=$~y (Re: Unexpected foo==bar errors)
From: Bart Schaefer <[email-masked]>
To: zsh workers <[email-masked]>
Date: Sun, 14 Feb 2016 12:10:12 -0800
List-Id: Zsh Workers List <zsh-workers.zsh.org>

On Feb 8,  8:16pm, Mikael Magnusson wrote:
} Subject: Re: Unexpected foo==bar errors
}
} On Mon, Feb 8, 2016 at 7:45 PM, Bart Schaefer <[email-masked]> wrote:
} > On Feb 8,  4:52am, Mikael Magnusson wrote:
} > } I wonder if there's anywhere in the completion system that depends on
} > } EQUALS being set... But maybe we should just 2> /dev/null the
} > } assignment since tilde expansion also prints errors. (_zattr and _zip
} > } also have this issue, presumably there are other places as well).

Looks like stderr is already redirected in _zattr.

} Well, considering that something simple as foo*.tar (expanding only to
} one file) also leaves $tf empty, I'd say it's better to leave $tf
} empty for any weird command substitutions as well, but suppress the
} error messages.

The following all use ${~param} in places where an error could occur if
the value looks like a process substitution:

   Completion/Base/Utility/_arguments
   Completion/Base/Widget/_correct_filename
   Completion/Base/Widget/_most_recent_file
   Completion/Unix/Command/_devtodo
   Completion/Unix/Command/_make
   Completion/Unix/Command/_ssh
   Completion/Unix/Command/_tar
   Completion/Unix/Command/_zip
   Completion/Unix/Type/_canonical_paths

If for some reason one used a process substitution to locate the muttrc
file, Completion/Unix/Type/_mailboxes might also have that issue, but I
think that's wildly unlikely.

Some of these might warrant a closer look to see if it's a larger issue
to proceed with the resulting empty string.

diff --git a/Completion/Base/Utility/_arguments b/Completion/Base/Utility/_arguments
index 87fb20e..687c0c4 100644
--- a/Completion/Base/Utility/_arguments
+++ b/Completion/Base/Utility/_arguments
@@ -36,7 +36,7 @@ if (( long )); then
 
   tmpargv=( "${(@)argv[1,long-1]}" )  # optspec's before --, if any
 
-  name=${~words[1]}
+  name=${~words[1]} 2>/dev/null
   [[ "$name" = [^/]*/* ]] && name="$PWD/$name"
 
   name="_args_cache_${name}"
diff --git a/Completion/Base/Widget/_correct_filename b/Completion/Base/Widget/_correct_filename
index 7431a48..3150ffc 100644
--- a/Completion/Base/Widget/_correct_filename
+++ b/Completion/Base/Widget/_correct_filename
@@ -28,7 +28,7 @@ fi
 
 if [[ $file = \~*/* ]]; then
   tilde=${file%%/*}
-  etilde=${~tilde}
+  etilde=${~tilde} 2>/dev/null
   file=${file/#$tilde/$etilde}
 fi
 
diff --git a/Completion/Base/Widget/_most_recent_file b/Completion/Base/Widget/_most_recent_file
index 68d1c91..e72cf5e 100644
--- a/Completion/Base/Widget/_most_recent_file
+++ b/Completion/Base/Widget/_most_recent_file
@@ -11,7 +11,7 @@
 local file tilde etilde
 if [[ $PREFIX = \~*/* ]]; then
   tilde=${PREFIX%%/*}
-  etilde=${~tilde}
+  etilde=${~tilde} 2>/dev/null
   # PREFIX and SUFFIX have full command line quoting in, but we want
   # any globbing characters which are quoted to stay quoted.
   eval "file=($PREFIX*$SUFFIX(om[${NUMERIC:-1}]N))"
diff --git a/Completion/Unix/Command/_devtodo b/Completion/Unix/Command/_devtodo
index 2800f4a..dbc64f8 100644
--- a/Completion/Unix/Command/_devtodo
+++ b/Completion/Unix/Command/_devtodo
@@ -9,7 +9,7 @@ typeset expl
 
 for ((i=2; i <= $#words; i++)) {
 	if [[ $words[$i] == '--database' ]]; then
-		todo_opts+=(--database ${~words[$((++i))]})
+		todo_opts+=(--database ${~words[$((++i))]}) 2>/dev/null
 	elif [[ $words[$i] == '--sort' ]]; then
 		todo_opts+=(--sort ${words[$((++i))]})
 	fi
diff --git a/Completion/Unix/Command/_make b/Completion/Unix/Command/_make
index 48befa7..c3f3961 100644
--- a/Completion/Unix/Command/_make
+++ b/Completion/Unix/Command/_make
@@ -129,7 +129,7 @@ _make-findBasedir () {
   do
     if [[ $@[index] == -C ]]
     then
-      file=${~@[index+1]};
+      file=${~@[index+1]} 2>/dev/null
       if [[ -z $file ]]
       then
         # make returns with an error if an empty arg is given
diff --git a/Completion/Unix/Command/_ssh b/Completion/Unix/Command/_ssh
index c6ede9e..1f8f62c 100644
--- a/Completion/Unix/Command/_ssh
+++ b/Completion/Unix/Command/_ssh
@@ -622,7 +622,7 @@ _ssh_hosts () {
       ${opt_args[-l]:+"users=${opt_args[-l]:q}"} hosts "$@" && return
   fi
   if (( ind = ${words[(I)-F]} )); then
-    config=${~words[ind+1]}
+    config=${~words[ind+1]} 2>/dev/null
   else
     config="$HOME/.ssh/config"
   fi
diff --git a/Completion/Unix/Command/_tar b/Completion/Unix/Command/_tar
index 1e99ac0..4a24048 100644
--- a/Completion/Unix/Command/_tar
+++ b/Completion/Unix/Command/_tar
@@ -79,7 +79,7 @@ else
     tf=${~words[tmp+1]}
     _tar_cmd="f$_tar_cmd"
   fi
-fi
+fi 2>/dev/null
 
 # See if we should use a path prefix.  We have to use eval as the dir can
 # be any unevaluated thing which appears on the command line, including a
diff --git a/Completion/Unix/Command/_zip b/Completion/Unix/Command/_zip
index 171daf0..1040fa9 100644
--- a/Completion/Unix/Command/_zip
+++ b/Completion/Unix/Command/_zip
@@ -120,7 +120,7 @@ case $state in
 	zipfile=$testfile.ZIP
       else
 	return 1
-      fi
+      fi 2>/dev/null
       if [[ $zipfile !=  $_zip_cache_name ]]; then
 	_zip_cache_name="$zipfile"
 	_zip_cache_list=( ${(f)"$(zipinfo -1 $_zip_cache_name)"} )
diff --git a/Completion/Unix/Type/_canonical_paths b/Completion/Unix/Type/_canonical_paths
index d23b913..e4a725b 100644
--- a/Completion/Unix/Type/_canonical_paths
+++ b/Completion/Unix/Type/_canonical_paths
@@ -61,7 +61,7 @@ _canonical_paths_get_canonical_path() {
 _canonical_paths_add_paths () {
   local origpref=$1 expref rltrim curpref canpref subdir
   [[ $2 != add ]] && matches=()
-  expref=${~origpref}
+  expref=${~origpref} 2>/dev/null
   [[ $origpref == (|*/). ]] && rltrim=.
   curpref=${${expref%$rltrim}:-./}
   if zstat $curpref >&/dev/null; then