patch 7.4.1322
Problem: Crash when unletting the variable that holds the channel in a
callback function. (Christian Robinson)
Solution: Increase the reference count while invoking the callback.
diff --git a/src/proto/eval.pro b/src/proto/eval.pro
index d1f5c3c..e63205e 100644
--- a/src/proto/eval.pro
+++ b/src/proto/eval.pro
@@ -79,6 +79,7 @@
dictitem_T *dict_find(dict_T *d, char_u *key, int len);
char_u *get_dict_string(dict_T *d, char_u *key, int save);
long get_dict_number(dict_T *d, char_u *key);
+int channel_unref(channel_T *channel);
int string2float(char_u *text, float_T *value);
char_u *get_function_name(expand_T *xp, int idx);
char_u *get_expr_name(expand_T *xp, int idx);