End an address fragment at a tab

On the :Tags path the rest of the line carries the extension fields, and an
unterminated pattern took them into the search, so '/^foo' became
'/^foo<Tab>f<Tab>file:' and found nothing. A helptags address, the case the
fragment is for, holds no tab.

autoload/fzf/vim.vim

@@ -561,7 +561,7 @@ endfunction
 " a fragment is the cut, and it would match some other line. Running to the end
 " of the line it takes any '|' or ';' with it, so it cannot chain a command.
 let s:tag_address_part = '\%(\d\+\|/\%(\\.\|[^/\\]\)*/\|?\%(\\.\|[^?\\]\)*?\)'
-let s:tag_address_open = '\%(/\%(\\.\|[^/\\]\)*\|?\%(\\.\|[^?\\]\)*\)'
+let s:tag_address_open = '\%(/\%(\\.\|[^/\\\t]\)*\|?\%(\\.\|[^?\\\t]\)*\)'
 function! s:tag_address(rest, whole)
   " :BTags aligns its columns, so its field arrives padded, and a tags file with
   " CRLF endings leaves a carriage return, which s:strip() keeps
@@ -575,7 +575,7 @@ function! s:tag_address(rest, whole)
   if !empty(address)
     return address
   endif
-  return a:whole ? matchstr(rest, '^'.s:tag_address_open.'$') : ''
+  return a:whole ? matchstr(rest, '^'.s:tag_address_open.'\ze\%(\t\|$\)') : ''
 endfunction
 
 " [key, [filename, [stay_on_edit: 0]]]