3 files changed, 23 insertions, 14 deletions
diff --git a/test/functional/ex_cmds/recover_spec.lua b/test/functional/ex_cmds/recover_spec.lua
index b92739e40e..a24a60af81 100644
--- a/test/functional/ex_cmds/recover_spec.lua
+++ b/test/functional/ex_cmds/recover_spec.lua
@@ -47,7 +47,8 @@ describe(':preserve', function()
 
     --TODO(justinmk): this is an ugly hack to force `helpers` to support
     --multiple sessions.
-    local nvim2 = helpers.spawn({helpers.nvim_prog, '-u', 'NONE', '--embed'})
+    local nvim2 = helpers.spawn({helpers.nvim_prog, '-u', 'NONE', '--embed'},
+                                true)
     helpers.set_session(nvim2)
 
     source(init)
diff --git a/test/functional/helpers.lua b/test/functional/helpers.lua
index 23581ba4d2..79f1feb7b5 100644
--- a/test/functional/helpers.lua
+++ b/test/functional/helpers.lua
@@ -178,12 +178,27 @@ local function rawfeed(...)
   end
 end
 
-local function spawn(argv)
+local function merge_args(...)
+  local i = 1
+  local argv = {}
+  for anum = 1,select('#', ...) do
+    local args = select(anum, ...)
+    if args then
+      for _, arg in ipairs(args) do
+        argv[i] = arg
+        i = i + 1
+      end
+    end
+  end
+  return argv
+end
+
+local function spawn(argv, merge)
   local loop = Loop.new()
   local msgpack_stream = MsgpackStream.new(loop)
   local async_session = AsyncSession.new(msgpack_stream)
   local session = Session.new(async_session)
-  loop:spawn(argv)
+  loop:spawn(merge and merge_args(prepend_argv, argv) or argv)
   return session
 end
 
@@ -382,4 +397,5 @@ return {
   rmdir = rmdir,
   mkdir = lfs.mkdir,
   exc_exec = exc_exec,
+  merge_args = merge_args,
 }
diff --git a/test/functional/shada/helpers.lua b/test/functional/shada/helpers.lua
index d37e84f156..b3153ca7f1 100644
--- a/test/functional/shada/helpers.lua
+++ b/test/functional/shada/helpers.lua
@@ -2,7 +2,7 @@ local helpers = require('test.functional.helpers')
 local spawn, set_session, nvim, nvim_prog, nvim_command, nvim_eval =
   helpers.spawn, helpers.set_session, helpers.nvim, helpers.nvim_prog,
   helpers.command, helpers.eval
-local write_file = helpers.write_file
+local write_file, merge_args = helpers.write_file, helpers.merge_args
 
 local msgpack = require('MessagePack')
 
@@ -16,18 +16,10 @@ local function nvim_argv()
                      '--cmd', additional_cmd,
                      '--embed'}
   if helpers.prepend_argv then
-    ret = {}
-    for i, v in ipairs(helpers.prepend_argv) do
-      ret[i] = v
-    end
-    local shift = #ret
-    for i, v in ipairs(nvim_argv) do
-      ret[i + shift] = v
-    end
+    return merge_args(helpers.prepend_argv, nvim_argv)
   else
-    ret = nvim_argv
+    return nvim_argv
   end
-  return ret
 end
 
 local session = nil