Bug/Patch view.el

[Jonathan Goldblatt]

Here is a little test script that demonstrates some problems in
view-search-no-match-lines followed by a patch to replace it.

Just run the form to see the anomalies.  It generates a file that
contains many lines "abc" with a very few "123" lines
interspered.  If you do /!a looking for a non-abc line you wind
up with the highlight on the line after the 123 line.  If you do
it twice and then try to go backwards with a p, the previous hit
isn't found at all??

The test script also shows problems with sit-for in a windowed
environment.  If you just do a sit-for it doesn't wait at all.
It seems like the work-around of doing a short sit-for followed
by another sit-for seems to wait much longer than the specified
time.  Also tried to use display-buffer with a specified frame
and didn't get the test buffer showing up in the new frame??

This was on 

Linux version 2.4.21 (root@xeon.localdomain) (gcc version 3.2.3
20030316 (Debian prerelease)) #1 Sat Mar 13 13:25:10 EST 2004

GNU Emacs 21.4.1 (i386-pc-linux-gnu, X toolkit, Xaw3d scroll
bars) of 2005-03-17 on trouble, modified by Debian


Hope this helps.

Test script:

(let* ((test-buffer (generate-new-buffer "test"))
       (test-frame
        (let ((pop-up-frames t))
          (pop-to-buffer test-buffer 't)
          (window-frame (selected-window))))
       (i 1)
       (j 1))
      (progn
        (with-current-buffer test-buffer
          (while (< j 4)
            (while (< i 200)
              (insert "abc\n")
              (setq i (1+ i)))
            (insert "123\n")
            (setq i 1)
            (setq j (1+ j)))
          (view-mode)
          (goto-char (point-min))
          (View-search-regexp-forward 1 "!a")
          (message
"Simulated /!a.in view mode.
Notice highlight one line too far.
Line 200 is \"123\"
Press any key to continue.")
          (sit-for 1)
          (if (not(sit-for 60))
          (read-char))
          (View-search-last-regexp-forward 1)
          (message
"Simulated n.
Notice highlight one line too far.
Current line is 401.
Press any key to continue.")
          (sit-for 1)
          (if (not(sit-for 60))
              (read-char))
          (View-search-last-regexp-backward 1)
          (sit-for 1)
          (if (not(sit-for 5))
              (read-char))
          (message
"That was a simulated p.
Notice can't find line 200?!.
Press any key to end.")
          (sit-for 1)
          (if (not(sit-for 60))
              (read-char))
          (if (y-or-n-p "Remove buffer?")
              (kill-buffer test-buffer))
          (if (y-or-n-p "Remove frame?")
              (delete-frame test-frame)))))

Here's the patch:


2007-09-12  Jonathan Goldblatt  <jonathangoldblatt@yahoo.com>


        * view.el (view-search-no-match-lines): Rewrote to work
          in more, possibly all, cases.  

*** /usr/share/emacs/21.4/lisp/view.el  Tue Sep  4 08:52:36 2001
--- /home/jonathan/.emacs.d/lisp/view.el        Thu Sep  6 16:37:46 2007
***************
*** 972,995 ****
  
  (defun view-search-no-match-lines (times regexp)
    ;; Search for the TIMESt occurrence of line with no match for REGEXP.
!   (let ((back (and (< times 0) (setq times (- times)) -1))
!       n)
!     (while (> times 0)
!       (save-excursion (beginning-of-line (if back (- times) (1+ times)))
!                     (setq n (point)))
!       (setq times
!           (cond
!            ((< (count-lines (point) n) times) -1) ; Not enough lines.
!            ((or (null (re-search-forward regexp nil t back))
!                 (if back (and (< (match-end 0) n)
!                               (> (count-lines (match-end 0) n) 1))
!                   (and (< n (match-beginning 0))
!                        (> (count-lines n (match-beginning 0)) 1))))
!             0)                        ; No match within lines.
!            (back (count-lines (max n (match-beginning 0)) (match-end 0)))
!            (t (count-lines (match-beginning 0) (min n (match-end 0))))))
!       (goto-char n))
!     (and (zerop times) (looking-at "^.*$"))))
  
  
  (provide 'view)
--- 987,1026 ----
  
  (defun view-search-no-match-lines (times regexp)
    ;; Search for the TIMESt occurrence of line with no match for REGEXP.
!   ;; times > 0 for forward search; < 0 for backward search
!   (let ((count (abs times))
!       (hit-count 0)
!       (fwd-one                        ;parm used by forward-line to
!                                       ;move 1 line in search
!                                       ;direction
!        (if (> times 0) 1 -1))
!       (bkwd-one                       ;parm used by forward-line to
!                                       ;move 1 line in opposite
!                                       ;direction of search
!        (if (> times 0) -1 1))
!       end-search
!       searching)
!     (while (> count 0)
!       (setq searching 't)
!       (while searching
!       (forward-line fwd-one)
!       (if (/= 0 (forward-line fwd-one)) ;not bob or eob
!             (setq searching 'nil
!                   count 0)
!         (forward-line bkwd-one)
!         (forward-line 1)
!         (setq end-search (point))
!         (forward-line -1)             ;reset point
!         (setq searching (re-search-forward regexp end-search 't))
!         (if (not searching)
!             (progn
!               (forward-line 0)
!               (setq hit-count (1+ hit-count))))))
!       (setq count (1- count)))
!     (re-search-forward "^.*\n" (point-max) 't) ; setup to highlight
!                                              ; line
!     (forward-line -1)                 ; reset point after search
!     (= hit-count (abs times))))
  
  
  (provide 'view)