david-christiansen / helm-pages Goto Github PK

Problem

There is an issue with the current value of POS in helm-pages-get-pages. According to the documentation, POS is the beginning of a page. However, except for the first page, the value of POS is actually the position before the page-delimiter.

Example

For example, suppose that ^L is the page-delimiter, and we have a buffer as follows:

First page
Foo
^L
Second page
Bar
^L
Third page
Baz

Let (n) be the position of the beginning of the nth page. Then I would expect:

(1)First page
Foo
^L
(2)Second page
Bar
^L
(3)Third page
Baz

Instead, we currently have:

(1)First page
Foo
(2)^L
Second page
Bar
(3)^L
Third page
Baz

Consequence

The consequence of this inconsistency is that the helm-pages-goto-page and helm-pages-narrow-to-page functions have to call forward-line to position the cursor as the the user would expect, but this causes the cursor for the first page to be positioned on the second line, not the first.

Try it: call helm-pages-goto-page on First page in the above example while using helm-pages. Let (|) indicate the cursor. Then I would expect:

(|)First page
Foo
^L
Second page
Bar
^L
Third page
Baz

Instead, we currently have:

First page
(|)Foo
^L
Second page
Bar
^L
Third page
Baz

Solution

• Change helm-pages-get-pages to:

(defun helm-pages-get-pages ()
  "Get a list of (POS . HEADER) pairs, where POS denotes the
beginning of a page and HEADER is the contents of the first
non-blank line in that page."
  (with-helm-current-buffer
    (save-excursion
      (save-restriction
    (widen)
    (goto-char (point-min))
    (let ((pages (list (cons (point)
                 (helm-pages-get-next-header)))))
      (while (re-search-forward page-delimiter nil t)
            (forward-line)
        (push (cons (point)
            (helm-pages-get-next-header))
          pages))
      (nreverse pages))))))

• Remove forward-line from helm-pages-goto-page and helm-pages-narrow-to-page.