patch 7.4.1288
Problem:    ch_sendexpr() does not use JS encoding.
Solution:   Use the encoding that fits the channel mode.  Refuse using
            ch_sendexpr() on a raw channel.
diff --git a/src/proto/channel.pro b/src/proto/channel.pro
index 693d2c2..4de1720 100644
--- a/src/proto/channel.pro
+++ b/src/proto/channel.pro
@@ -24,4 +24,5 @@
 int channel_select_check(int ret_in, void *rfds_in);
 int channel_parse_messages(void);
 int set_ref_in_channel(int copyID);
+ch_mode_T channel_get_mode(int idx);
 /* vim: set ft=c : */