missing characters when horizontal scrolling if fringe-mode off + truncate-lines + tab indentation

[strager]

Issue type

• Bug report

Environment

Emacs version: GNU Emacs 29.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.38, cairo version 1.16.0) (built with Nix) Operating System: Linux Mint 21.2 Victoria (based on Ubuntu 22.04 Jammy) Evil version: 1.15.0 Evil installation type: manual Graphical/Terminal: X Tested in a make emacs session (see CONTRIBUTING.md): No

Reproduction steps

init.el:

(package-initialize)
(evil-mode 1)
(fringe-mode 0)
(setq-default truncate-lines t)

File:

	AssertStringsEqual(t, err.Error(), "could not find '## Unreleased' heading in changelog")
// NOTE: The above line has a leading TAB (not spaces)

Open the file in Emacs and run these Evil commands:

• $ (go to end of line)
• F" (go to the last ")
• ; (repeat search; go to the first ")

Expected behavior

Buffer scrolls horizontally. I can see some characters to the left and to the right. Due to truncate-lines, I see $ on the left-most column and $ on the right-most column.

Actual behavior

Buffer scrolls horizontally. I can see some characters to the left and to the right, but some characters on the right are missing. Due to truncate-lines, I see $ on the left-most column but there is no $ on the right-most column.

Screenshot:

Further notes

Works as expected with fringe-mode enabled.

Works as expected if tabs are replaced with spaces.

Specific repro might depend on window size and font size.