From cd7303dcaffb7b7ab2cfc5ef648904ce6cee1514 Mon Sep 17 00:00:00 2001
From: Ches Martin <ches@whiskeyandgrits.net>
Date: Fri, 13 Jan 2017 12:53:56 +0700
Subject: [PATCH] Work around a startup error on Vim < 7.4

Closes #369, refs #368 (1b32e85f)

There are other uses of Vim 7.4+ Python API in our code, this does not
attempt to fix all of them. This just avoids a particularly bad failure
mode during Vim startup.
---
 plugin/ensime.vim | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/plugin/ensime.vim b/plugin/ensime.vim
index 6e55e16..f23b67d 100644
--- a/plugin/ensime.vim
+++ b/plugin/ensime.vim
@@ -21,15 +21,28 @@ endif
 function! s:DependenciesValid() abort
     python <<PY
 import vim
+
+# TODO: officially drop Vim < 7.4 support, inform users and don't load plugin
+VIM74 = hasattr(vim, 'vars')
+
 try:
     import sexpdata
     import websocket
 
-    vim.vars['ensime_deps_valid'] = True
+    if VIM74:
+        vim.vars['ensime_deps_valid'] = True
+    else:
+        vim.command('let g:ensime_deps_valid = 1')
+
     del sexpdata # Clean up the shared interpreter namespace
     del websocket
 except ImportError:
-    vim.vars['ensime_deps_valid'] = False
+    if VIM74:
+        vim.vars['ensime_deps_valid'] = False
+    else:
+        vim.command('let g:ensime_deps_valid = 0')
+
+del VIM74
 PY
 
     return g:ensime_deps_valid