[PATCH] emacs: Correct message/header/citation/signature hiding

[David Edmondson]

Set `buffer-invisibility-spec' to `nil' (a list) if it is just `t'
before inserting any body parts, otherwise removing items from
`buffer-invisibility-spec' (which is what
`notmuch-show-headers-visible' and `notmuch-show-message-visible' do)
is a no-op and has no effect. This caused threads with only matching
messages to have those messages hidden initially because
`buffer-invisibility-spec' stayed `t'.
---

Carl, we need this fix before 0.3 is released. The bug has always
existed in the JSON based UI and is now exposed because previously
there was always a call to `add-to-invisibility-spec' (for the
headers), which transformed `buffer-invisiliblty-spec' from `t' to a
list. That doesn't always happen now (only calls to
`remove-from-invisibility-spec'), so the variable could get left as
`t'.

 emacs/notmuch-show.el |   16 ++++++++++++++++
 1 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index f958a30..f9d6c93 100644
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -382,6 +382,22 @@ current buffer, if possible."
 	(headers-invis-spec (notmuch-show-make-symbol "header"))
 	(message-invis-spec (notmuch-show-make-symbol "message")))
 
+    ;; Set `buffer-invisibility-spec' to `nil' (a list), otherwise
+    ;; removing items from `buffer-invisibility-spec' (which is what
+    ;; `notmuch-show-headers-visible' and
+    ;; `notmuch-show-message-visible' do) is a no-op and has no
+    ;; effect. This caused threads with only matching messages to have
+    ;; those messages hidden initially because
+    ;; `buffer-invisibility-spec' stayed `t'.
+    ;;
+    ;; This needs to be set here (rather than just above the call to
+    ;; `notmuch-show-headers-visible') because some of the part
+    ;; rendering or body washing functions
+    ;; (e.g. `notmuch-wash-text/plain-citations') manipulate
+    ;; `buffer-invisibility-spec').
+    (when (eq buffer-invisibility-spec t)
+      (setq buffer-invisibility-spec nil))
+
     (setq message-start (point-marker))
 
     (notmuch-show-insert-headerline headers
-- 
1.7.0