commit 0850f95a44aae5311eed0944e72ad853eab721e5
Author: Greg Neagle <gregneagle@mac.com>
Date:   Thu Jan 3 09:39:07 2019 -0800

    Also precache items where precache=True and needs_update=True

diff --git a/code/client/munkilib/updatecheck/download.py b/code/client/munkilib/updatecheck/download.py
index 020c7ea1..656b1b49 100644
--- a/code/client/munkilib/updatecheck/download.py
+++ b/code/client/munkilib/updatecheck/download.py
@@ -368,10 +368,12 @@ def _installinfo():
 
 def _items_to_precache(install_info):
     '''Returns a list of items from InstallInfo.plist's optional_installs
-    that have precache=True and installed=False'''
+    that have precache=True and (installed=False or needs_update=True)'''
     optional_install_items = install_info.get('optional_installs', [])
     precache_items = [item for item in optional_install_items
-                      if item.get('precache') and not item.get('installed')]
+                      if item.get('precache')
+                      and (not item.get('installed')
+                           or item.get('needs_update'))]
     return precache_items