0. emacs -Q
1. Evaluate the following sexp:
(let ((buf (get-buffer-create "*Widget Test*")))
(switch-to-buffer buf)
(dolist (el '("First" "Second" "Third"))
(widget-create 'push-button el))
(use-local-map widget-keymap)
(widget-setup)
(goto-char (point-min)))
Now the current buffer is *Widget Test* containing three push-button
widgets labeled "First", "Second", and "Third", and point is at the
start of the first widget, at BOB.
2. Hit the TAB key (bound to widget-forward) three times: this moves
point successively from "First" to "Second" to "Third" and then back to
"First" -- but on returning to the initial position after the third TAB,
a beginning-of-buffer error is also signaled.
3. Likewise, hitting S-TAB (bound to widget-backward) three times moves
backwards across the widgets, from "Third" to "Second" to "First", again
signaling a beginning-of-buffer error after the last S-TAB.
These beginning-of-buffer errors are due to widget-move (the workhorse
behind widget-forward and widget-backward) calling backward-char in a
loop without checking for BOB. The attached patch fixes this. The
patch also includes additions to widget-test-widget-move (from which
most of the above sexp was taken) that test moving to a widget at BOB.
(If the patch is acceptable, whoever commits it should use the correct
bug# before pushing it, or I can do that myself.)
2024-03-22 Stephen Berman <stephen.berman@gmx.net>
Prevent error on tabbing to widget at beginning of buffer (bug#xxxxx)
* lisp/wid-edit.el (widget-move): Don't move backward when at
beginning of buffer, and keep point on widget's left side.
* test/lisp/wid-edit-tests.el (widget-test-widget-move): Adds
checks that moving to a widget at beginning of buffer does not
signal a beginning-of-buffer error.
widget-move.diff
Description: Text Data
In GNU Emacs 30.0.50 (build 3, x86_64-pc-linux-gnu, GTK+ Version 3.24.38, cairo version 1.18.0) of 2024-03-22 built on strobelfs2 Repository revision: c1530a2e4973005633ebe00d447f1f3aa1200301 Repository branch: master Windowing system distributor 'The X.Org Foundation', version 11.0.12101009 System Description: Linux From Scratch r12.0-112 Configured using: 'configure -C --with-xwidgets 'CFLAGS=-Og -g3' PKG_CONFIG_PATH=/opt/qt5/lib/pkgconfig' Configured features: ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG JSON LCMS2 LIBSYSTEMD LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY PDUMPER PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS TREE_SITTER WEBP X11 XDBE XIM XINPUT2 XPM XWIDGETS GTK3 ZLIB
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