emacs: Fix `notmuch-hello-insert-tags' to correctly draw the tags.

The fix in 1e1871154341cdd3413fe3f32e3aae477826d815 broke end-of-row
wrapping when drawing the table of tags/saved searches. Fix that and
improve the readability of the matrix reflection code to hasten future
debugging.
(cherry picked from commit 08561d8ae133704fcf15edbdd47f15474dc030d5)

diff --git a/emacs/notmuch-hello.el b/emacs/notmuch-hello.el
index 1b59ef19941656a30d468ce8e848ac5107c5f980..6a1c56e52b341c045a5ff038da79dbf556dd1ecb 100644 (file)
--- a/emacs/notmuch-hello.el
+++ b/emacs/notmuch-hello.el
@@ -118,23 +118,24 @@
   (+ (/ dividend divisor)
      (if (> (% dividend divisor) 0) 1 0)))
 
-(defun notmuch-hello-reflect (list width)
-  "Reflect a `width' wide matrix represented by `list' along the
+(defun notmuch-hello-reflect-generate-row (ncols nrows row list)
+  (let ((len (length list)))
+    (loop for col from 0 to (- ncols 1)
+         collect (let ((offset (+ (* nrows col) row)))
+                   (if (< offset len)
+                       (nth offset list)
+                     ;; Don't forget to insert an empty slot in the
+                     ;; output matrix if there is no corresponding
+                     ;; value in the input matrix.
+                     nil)))))
+
+(defun notmuch-hello-reflect (list ncols)
+  "Reflect a `ncols' wide matrix represented by `list' along the
 diagonal."
   ;; Not very lispy...
-  (let* ((len (length list))
-        (nrows (notmuch-hello-roundup len width)))
+  (let ((nrows (notmuch-hello-roundup (length list) ncols)))
     (loop for row from 0 to (- nrows 1)
-         append (loop for col from 0 to (- width 1)
-                      ;; How could we calculate the offset just once
-                      ;; per inner-loop?
-                      if (< (+ (* nrows col) row) len)
-                      collect (nth (+ (* nrows col) row) list)
-                      else
-                      ;; Don't forget to insert an empty slot in the
-                      ;; output matrix if there is no corresponding
-                      ;; value in the input matrix.
-                      collect nil))))
+         append (notmuch-hello-reflect-generate-row ncols nrows row list))))
 
 (defun notmuch-hello-widget-search (widget &rest ignore)
   (notmuch-search (widget-get widget
@@ -179,10 +180,10 @@ diagonal."
                ;; can just insert `(- widest (length name))' spaces -
                ;; the column separator is included in the button if
                ;; `(equal widest (length name)'.
-               (widget-insert (make-string (- widest (length name)) ? )))
-             (setq count (1+ count))
-             (if (eq (% count tags-per-line) 0)
-                 (widget-insert "\n"))))
+               (widget-insert (make-string (- widest (length name)) ? ))))
+           (setq count (1+ count))
+           (if (eq (% count tags-per-line) 0)
+               (widget-insert "\n")))
          reordered-list)
 
     ;; If the last line was not full (and hence did not include a