patch 7.4.1827
Problem: No error when invoking a callback when it's not safe.
Solution: Add an error message. Avoid the error when freeing a channel.
diff --git a/src/structs.h b/src/structs.h
index a2b38bf..24d819b 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -1419,6 +1419,8 @@
int ch_to_be_closed; /* When TRUE reading or writing failed and
* the channel must be closed when it's safe
* to invoke callbacks. */
+ int ch_to_be_freed; /* When TRUE channel must be freed when it's
+ * safe to invoke callbacks. */
int ch_error; /* When TRUE an error was reported. Avoids
* giving pages full of error messages when
* the other side has exited, only mention the