[PATCH] Fix bug, and clean up code duplication, in adding or removing tag by region.

[Jesse Rosenthal]

There was a bug in notmuch-search-{add,remove}-tag-region, which would
not behave correctly if the region went beyond the last message. Now,
instead of simply iterating to the last line of the region, these
functions will iterate to the minimum of the last line of the region
and the last possible line, i.e.

(- (line-number-at-pos (point-max)) 2)

Also clean up code duplication, as per Carl's suggestion, by making
notmuch-search-{add/remove}-tag-thread a special case of the -region
commands, where the region in question is between (point) and (point).
---
 emacs/notmuch.el |   26 ++++++++++++++------------
 1 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/emacs/notmuch.el b/emacs/notmuch.el
index 517c53a..be09f42 100644
--- a/emacs/notmuch.el
+++ b/emacs/notmuch.el
@@ -399,10 +399,11 @@ Complete list of currently available key bindings:
 (defun notmuch-search-properties-in-region (property beg end)
   (save-excursion
     (let ((output nil)
-	  (last-line (line-number-at-pos end)))
+	  (last-line (line-number-at-pos end))
+	  (max-line (- (line-number-at-pos (point-max)) 2)))
       (goto-char beg)
       (beginning-of-line)
-      (while (<= (line-number-at-pos) last-line)
+      (while (<= (line-number-at-pos) (min last-line max-line))
 	(setq output (cons (get-text-property (point) property) output))
 	(forward-line 1))
       output)))
@@ -497,38 +498,39 @@ and will also appear in a buffer named \"*Notmuch errors*\"."
 (defun notmuch-search-get-tags-region (beg end)
   (save-excursion
     (let ((output nil)
-	  (last-line (line-number-at-pos end)))
+	  (last-line (line-number-at-pos end))
+	  (max-line (- (line-number-at-pos (point-max)) 2)))
       (goto-char beg)
-      (while (<= (line-number-at-pos) last-line)
+      (while (<= (line-number-at-pos) (min last-line max-line))
 	(setq output (append output (notmuch-search-get-tags)))
 	(forward-line 1))
       output)))
 
 (defun notmuch-search-add-tag-thread (tag)
-  (notmuch-call-notmuch-process "tag" (concat "+" tag) (notmuch-search-find-thread-id))
-  (notmuch-search-set-tags (delete-dups (sort (cons tag (notmuch-search-get-tags)) 'string<))))
+  (notmuch-search-add-tag-region tag (point) (point)))
 
 (defun notmuch-search-add-tag-region (tag beg end)
   (let ((search-id-string (mapconcat 'identity (notmuch-search-find-thread-id-region beg end) " or ")))
     (notmuch-call-notmuch-process "tag" (concat "+" tag) search-id-string)
     (save-excursion
-      (let ((last-line (line-number-at-pos end)))
+      (let ((last-line (line-number-at-pos end))
+	    (max-line (- (line-number-at-pos (point-max)) 2)))
 	(goto-char beg)
-	(while (<= (line-number-at-pos) last-line)
+	(while (<= (line-number-at-pos) (min last-line max-line))
 	  (notmuch-search-set-tags (delete-dups (sort (cons tag (notmuch-search-get-tags)) 'string<)))
 	  (forward-line))))))
 
 (defun notmuch-search-remove-tag-thread (tag)
-  (notmuch-call-notmuch-process "tag" (concat "-" tag) (notmuch-search-find-thread-id))
-  (notmuch-search-set-tags (delete tag (notmuch-search-get-tags))))
+  (notmuch-search-remove-tag-region tag (point) (point)))
 
 (defun notmuch-search-remove-tag-region (tag beg end)
   (let ((search-id-string (mapconcat 'identity (notmuch-search-find-thread-id-region beg end) " or ")))
     (notmuch-call-notmuch-process "tag" (concat "-" tag) search-id-string)
     (save-excursion
-      (let ((last-line (line-number-at-pos end)))
+      (let ((last-line (line-number-at-pos end))
+	    (max-line (- (line-number-at-pos (point-max)) 2)))
 	(goto-char beg)
-	(while (<= (line-number-at-pos) last-line)
+	(while (<= (line-number-at-pos) (min last-line max-line))
 	  (notmuch-search-set-tags (delete tag (notmuch-search-get-tags)))
 	  (forward-line))))))
 
-- 
1.6.5.3