share/functions: account for the possibility of mktemp failure.

share/functions/edit_command_buffer.fish

@@ -1,5 +1,6 @@
 function edit_command_buffer --description 'Edit the command buffer in an external editor'
     set -l f (mktemp)
+    or return 1
     if set -q f[1]
         mv $f $f.fish
         set f $f.fish

share/functions/funced.fish

@@ -80,6 +80,7 @@ function funced --description 'Edit function definition'
     set -q TMPDIR
     or set -l TMPDIR /tmp
     set -l tmpdir (mktemp -d $TMPDIR/fish.XXXXXX)
+    or return 1
     set -l tmpname $tmpdir/$funcname.fish
 
     if functions -q -- $funcname

share/functions/help.fish

@@ -169,6 +169,7 @@ function help --description 'Show help for the fish shell'
             set -q TMPDIR
             or set -l TMPDIR /tmp
             set -l tmpdir (mktemp -d $TMPDIR/help.XXXXXX)
+            or return 1
             set -l tmpname $tmpdir/help.html
             echo '<meta http-equiv="refresh" content="0;URL=\''$clean_url'\'" />' >$tmpname
             set page_url file://$tmpname

share/functions/psub.fish

@@ -26,7 +26,7 @@ function psub --description "Read from stdin into a file and output the filename
         # that the command substitution exits without needing to wait for
         # all the commands to exit.
         set dirname (mktemp -d $tmpdir/.psub.XXXXXXXXXX)
-        or return
+        or return 1
         set filename $dirname/psub.fifo"$_flag_suffix"
         command mkfifo $filename
         # Note that if we were to do the obvious `cat >$filename &`, we would deadlock
@@ -35,9 +35,11 @@ function psub --description "Read from stdin into a file and output the filename
         command tee $filename >/dev/null &
     else if test -z "$_flag_suffix"
         set filename (mktemp $tmpdir/.psub.XXXXXXXXXX)
+        or return 1
         command cat >$filename
     else
         set dirname (mktemp -d $tmpdir/.psub.XXXXXXXXXX)
+        or return 1
         set filename "$dirname/psub$_flag_suffix"
         command cat >$filename
     end