CheckHealth: choose correct path for the latest version (#5446)

If multiple versions of a package are installed, the provider health check could
choose a wrong path:

  /usr/local/lib/python3.5/site-packages/neovim-0.1.10-py3.5.egg-info/PKG-INFO
  /usr/local/lib/python3.5/site-packages/neovim-0.1.9-py3.5.egg-info/PKG-INFO

Prior to this change :CheckHealth could falsely show 0.1.9 as the installed
version, since glob() doesn't enforce any predictable order.

Now we sort all potential paths numerically in descending order and just look at
the first path instead.

1 files changed, 15 insertions, 3 deletions

diff --git a/runtime/autoload/health/provider.vim b/runtime/autoload/health/provider.vim
index aadb2688b7..b1cfa8bf2b 100644
--- a/runtime/autoload/health/provider.vim
+++ b/runtime/autoload/health/provider.vim
@@ -104,15 +104,27 @@ function! s:version_info(python) abort
     return [python_version, 'unable to find neovim executable', pypi_version, 'unable to get neovim executable']
   endif
 
+  " Assuming that multiple versions of a package are installed, sort them
+  " numerically in descending order.
+  function! s:compare(metapath1, metapath2)
+    let a = matchstr(fnamemodify(a:metapath1, ':p:h:t'), '[0-9.]\+')
+    let b = matchstr(fnamemodify(a:metapath2, ':p:h:t'), '[0-9.]\+')
+    return a == b ? 0 : a > b ? 1 : -1
+  endfunction
+
   let nvim_version = 'unable to find neovim version'
   let base = fnamemodify(nvim_path, ':h')
-  for meta in glob(base.'-*/METADATA', 1, 1) + glob(base.'-*/PKG-INFO', 1, 1)
-    for meta_line in readfile(meta)
+  let metas = glob(base.'-*/METADATA', 1, 1) + glob(base.'-*/PKG-INFO', 1, 1)
+  let metas = sort(metas, 's:compare')
+
+  if !empty(metas)
+    for meta_line in readfile(metas[0])
       if meta_line =~# '^Version:'
         let nvim_version = matchstr(meta_line, '^Version: \zs\S\+')
+        break
       endif
     endfor
-  endfor
+  endif
 
   let version_status = 'unknown'
   if !s:is_bad_response(nvim_version) && !s:is_bad_response(pypi_version)