commit https://github.com/vim/vim/commit/910b8aac5dc4693c4508b7acd2cef0bbfac04242 Author: Bram Moolenaar <Bram@vim.org> Date: Tue Feb 16 21:03:07 2016 +0100 patch 7.4.1341 Problem: It's difficult to add more arguments to ch_sendraw() and ch_sendexpr(). Solution: Make the third option a dictionary.

--- a/src/structs.h
+++ b/src/structs.h
@@ -1373,11 +1373,12 @@ struct channel_S {
 };
 
 /*
- * Options for job commands.
+ * Options for job and channel commands.
  */
 typedef struct
 {
-    ch_mode_T	jo_mode;
+    ch_mode_T	jo_mode;	/* "mode" */
+    char_u	*jo_callback;	/* "callback", not allocated! */
 } jobopt_T;