Variable: mh-thread-history
mh-thread-history is a buffer-local variable defined in
mh-thread.el.gz.
Documentation
Variable to remember the transformations to the thread tree.
When new messages are added, these transformations are rewound, then the links are added from the newly seen messages. Finally the transformations are redone to get the new thread tree. This makes incremental threading easier.
Source Code
;; Defined in /usr/src/emacs/lisp/mh-e/mh-thread.el.gz
(defvar mh-thread-history ()
"Variable to remember the transformations to the thread tree.
When new messages are added, these transformations are rewound,
then the links are added from the newly seen messages. Finally
the transformations are redone to get the new thread tree. This
makes incremental threading easier.")