emacs: deal with unused lexical arguments and variables

The previous commit switched to lexical-binding but without dealing
with the new warnings about unused lexical arguments and variables.

This commit deals with most of them, in most cases by either removing
leftover bindings that are actually unnecessary, or by marking certain
arguments as "known to be unused" by prefixing their names with "_".

In the case of the functions named `notmuch-show-insert-...' the
amount of silencing that is required is a bit extreme and we might
want to investigate if there is a better way.

In the case of `notmuch-mua-mail', ignoring CONTINUE means that we do
not fully follow the intended behavior described in `compose-mail's
doc-string.

1 files changed, 5 insertions, 9 deletions

diff --git a/emacs/notmuch-tree.el b/emacs/notmuch-tree.el
index 1ed34801..e254593f 100644
--- a/emacs/notmuch-tree.el
+++ b/emacs/notmuch-tree.el
@@ -598,8 +598,7 @@ NOT change the database."
   "Show the current message (in whole window)."
   (interactive)
   (let ((id (notmuch-tree-get-message-id))
-	(inhibit-read-only t)
-	buffer)
+	(inhibit-read-only t))
     (when id
       ;; We close the window to kill off un-needed buffers.
       (notmuch-tree-close-message-window)
@@ -1033,19 +1032,17 @@ Complete list of currently available key bindings:
   (setq buffer-read-only t)
   (setq truncate-lines t))
 
-(defun notmuch-tree-process-sentinel (proc msg)
+(defun notmuch-tree-process-sentinel (proc _msg)
   "Add a message to let user know when \"notmuch tree\" exits."
   (let ((buffer (process-buffer proc))
 	(status (process-status proc))
-	(exit-status (process-exit-status proc))
-	(never-found-target-thread nil))
+	(exit-status (process-exit-status proc)))
     (when (memq status '(exit signal))
       (kill-buffer (process-get proc 'parse-buf))
       (when (buffer-live-p buffer)
 	(with-current-buffer buffer
 	  (save-excursion
-	    (let ((inhibit-read-only t)
-		  (atbob (bobp)))
+	    (let ((inhibit-read-only t))
 	      (goto-char (point-max))
 	      (when (eq status 'signal)
 		(insert "Incomplete search results (tree view process was killed).\n"))
@@ -1059,8 +1056,7 @@ Complete list of currently available key bindings:
   "Process and filter the output of \"notmuch show\" for tree view."
   (let ((results-buf (process-buffer proc))
 	(parse-buf (process-get proc 'parse-buf))
-	(inhibit-read-only t)
-	done)
+	(inhibit-read-only t))
     (if (not (buffer-live-p results-buf))
 	(delete-process proc)
       (with-current-buffer parse-buf