bug#57223: 29.0.50; python-nav-forward-block moves backward under certain conditions.

bug#57223: 29.0.50; python-nav-forward-block moves backward under certain conditions.

[kobarity]

[-- Attachment #1: Type: text/plain, Size: 2973 bytes --]

Hi,

The following steps move the point backward to the beginning of the line.

1. emacs -Q
2. Load the following Python file using M-x find-file

#+begin_src python
if True:
    pass
#+end_src

3. M-x forward-char
4. M-x python-nav-forward-block

This happens when:

- point is on the block-start line of the last block,
- point is at least one character after the beginning of block-start, and
- searching forward (positive ARG for python-nav-forward-block).

Attached is a patch to fix this issue.

Best Regards,

--

In GNU Emacs 29.0.50 (build 10, x86_64-pc-linux-gnu)
 of 2022-08-15 built on ubuntu
System Description: Ubuntu 22.04.1 LTS

Configured using:
 'configure --without-x --with-gnutls=ifavailable'

Configured features:
ACL LIBXML2 MODULES NOTIFY INOTIFY PDUMPER SECCOMP SOUND SQLITE3 THREADS
XIM ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Python

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  show-paren-mode: t
  electric-indent-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  line-number-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message mailcap yank-media puny dired
dnd dired-loaddefs rfc822 mml mml-sec password-cache epa epg rfc6068
epg-config gnus-util text-property-search time-date mm-decode mm-bodies
mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail
rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils python skeleton
derived json map rx cl-macs pcase subr-x comint regexp-opt ring
cl-loaddefs cl-lib ansi-color term/screen term/xterm xterm byte-opt gv
bytecomp byte-compile cconv rmc iso-transl tooltip eldoc paren electric
uniquify ediff-hook vc-hooks lisp-float-type elisp-mode tabulated-list
replace newcomment text-mode lisp-mode prog-mode register page tab-bar
menu-bar rfn-eshadow isearch easymenu timer select mouse jit-lock
font-lock syntax font-core term/tty-colors frame minibuffer nadvice seq
simple cl-generic indonesian philippine cham georgian utf-8-lang
misc-lang vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms
cp51932 hebrew greek romanian slovak czech european ethiopic indian
cyrillic chinese composite emoji-zwj charscript charprop case-table
epa-hook jka-cmpr-hook help abbrev obarray oclosure cl-preloaded button
loaddefs faces cus-face macroexp files window text-properties overlay
sha1 md5 base64 format env code-pages mule custom widget keymap
hashtable-print-readable backquote threads inotify multi-tty
make-network-process emacs)

Memory information:
((conses 16 70922 6831)
 (symbols 48 7269 0)
 (strings 32 19447 1974)
 (string-bytes 1 607324)
 (vectors 16 10328)
 (vector-slots 8 124429 7979)
 (floats 8 29 517)
 (intervals 56 210 0)
 (buffers 992 13))

[-- Attachment #2: fix-python-nav-forward-block.patch --]
[-- Type: application/octet-stream, Size: 2210 bytes --]

commit 48b77389ef9107a5b9eee9c23d2dab39ee3c1143
Author: kobarity <kobarity@gmail.com>
Date:   Mon Aug 15 22:46:58 2022 +0900

    Fix `python-nav-forward-block' moving backward under certain conditions
    
    * lisp/progmodes/python.el (python-nav-forward-block): Add check
    for not moving backward.

diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index 96f9d14832..44df3186b2 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -1822,7 +1822,8 @@ python-nav-forward-block
   (or arg (setq arg 1))
   (let ((block-start-regexp
          (python-rx line-start (* whitespace) block-start))
-        (starting-pos (point)))
+        (starting-pos (point))
+        (orig-arg arg))
     (while (> arg 0)
       (python-nav-end-of-statement)
       (while (and
@@ -1836,7 +1837,8 @@ python-nav-forward-block
               (python-syntax-context-type)))
       (setq arg (1+ arg)))
     (python-nav-beginning-of-statement)
-    (if (not (looking-at (python-rx block-start)))
+    (if (or (and (> orig-arg 0) (< (point) starting-pos))
+            (not (looking-at (python-rx block-start))))
         (and (goto-char starting-pos) nil)
       (and (not (= (point) starting-pos)) (point-marker)))))
 
diff --git a/test/lisp/progmodes/python-tests.el b/test/lisp/progmodes/python-tests.el
index d303050fad..9e8fa7f552 100644
--- a/test/lisp/progmodes/python-tests.el
+++ b/test/lisp/progmodes/python-tests.el
@@ -2942,6 +2942,22 @@ python-nav-forward-block-1
               (python-tests-look-at
                "if request.user.is_authenticated():" -1)))))
 
+(ert-deftest python-nav-forward-block-2 ()
+  (python-tests-with-temp-buffer
+   "
+if True:
+    pass
+"
+   (python-tests-look-at "if True:")
+   (should (not (save-excursion (python-nav-forward-block))))
+   (should (not (save-excursion (python-nav-forward-block -1))))
+   (forward-char)
+   (should (not (save-excursion (python-nav-forward-block))))
+   (should (= (save-excursion (python-nav-forward-block -1))
+              (progn
+                (end-of-line)
+                (python-tests-look-at "if True:" -1))))))
+
 (ert-deftest python-nav-forward-sexp-1 ()
   (python-tests-with-temp-buffer
    "

bug#57223: 29.0.50; python-nav-forward-block moves backward under certain conditions.

[Lars Ingebrigtsen]

kobarity <kobarity@gmail.com> writes:

> Attached is a patch to fix this issue.

Thanks; pushed to Emacs 29.