Fix bug in adding or removing tag by region.

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)

Tested-by: Carl Worth <cworth@cworth.org> Note that the old, buggy
behavior included infinite loops of emacs lisp code, so the new
behavior is significantly better than that.

1 files changed, 12 insertions, 8 deletions

diff --git a/emacs/notmuch.el b/emacs/notmuch.el
index 517c53a..178dea2 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)))
@@ -497,9 +498,10 @@ 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)))
@@ -512,9 +514,10 @@ and will also appear in a buffer named \"*Notmuch errors*\"."
   (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))))))
 
@@ -526,9 +529,10 @@ and will also appear in a buffer named \"*Notmuch errors*\"."
   (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))))))