I forgot to CC this to the bugtracker yesterday. Another rookie mistake :{
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From: Dave Kepler <lalop.lmao <at>
gmail.com>
To: Eli Zaretskii <eliz <at>
gnu.org>
Date: Tue, 13 Aug 2013 23:43:59 -0500
My apologies, that was a pretty serious omission. My emacs version was 24.3.1. I've just tried it with trunk and -Q, and I think I found a reliable way to duplicate it.
1. emacs -Q, you start with a scratch file. Delete the text in the scratch file.
2. Paste the following string, not including quotations:
"abc def ghi jkl mno pqr stu vwz yzabc def ghi jkl mno pqr stu vwz yzabc def ghi jkl mno pqr stu vwz yzabc def ghi jkl mno pqr stu vwz yzabc def ghi jkl mno pqr stu vwz yzabc def ghi jkl mno pqr stu vwz yzabc def ghi jkl mno pqr stu vwz yzabc def ghi jkl mno pqr abc def ghi jkl mno pqr stu vwz yzabc def ghi jkl mno pqr stu vwz yzabc def ghi jkl mno pqr stu vwz yzabc def ghi jkl mno pqr stu vwz yzabc def ghi jkl mno pqr stu vwz yzabc def ghi jkl mno pqr stu vwz yzabc def ghi jkl mno pqr stu vwz yzabc def ghi jkl mno pqr
"
The exact string should not matter, but:
a. The top line should be many short words. It should be long enough to perform step 3.
b. It should be followed by many empty lines
3. Scroll down so that the top of your window breaks that top line. That is, part of the top line should be above your window, so that you are only able to see the ending of the top line.
4. M-x linum-mode
5. M-x visual-line-mode
6. Move point to the end of the top line, and type anything
What should happen: the text in the topmost part of the top line is unmoved as you append text to the end of line
What does happen: the text in the topmost part of the top line will move horizontally as you append text.
Note: when I try creating a new file rather than using scratch, this bug does not happen when I append to the end of the top line. Rather, it happens when I scroll using mouse. If the bug duplication does not work as planned, please also try the following for step 6:
a. Scrolling with mouse
b. Appending text far below the top line
c. Moving point downward while at EOF
while watching the top line. Hopefully, my duplication instructions will work, however.
Thanks for your patience,
Dave