# ‘double backslash + newline’ collapses to ‘single backslash’ when I hit ‘edit’

When I try to edit Thorsten Donig's answer to 'large braces for specifying values of variables by condition', the following happens:

      0, & \text{if}\ a=1 \\
1, & \text{otherwise}


I get:

      0, & \text{if}\ a=1 \          1, & \text{otherwise}


Honestly, if it wasn't the part of the answer I was about to edit, I wouldn't have noticed. This is a serious problem since \\ is commonly found at the end of line in LaTeX.

I run FF35.0.1, no userscripts or stuff, on Fedora 20, MATE 1.8.1. Reported on more systems in more browsers, so it seems it's on the server side.

For anybody testing it: Please do not actually edit the answer! It seems to be a problem only for posts last modified in some given period of time, and you could spoil it! Thanks :-)

• I see the same in Chromium 40 on Kubuntu 14.04, for Leo Liu's answer as well. Mar 11 '15 at 12:15
• I see the same problem with Google Chrome Version 39.0.2171.99 m, with and without my userscripts enabled, on Windows 7 Professional. Mar 11 '15 at 12:17
• I wonder if this is related at all to meta.tex.stackexchange.com/questions/5978/…?
– Joseph Wright Mod
Mar 11 '15 at 12:35
• @JosephWright may well be, I thought about it as well, but didn't get myself to find the bug report actually. Thanks for doing that.
– yo'
Mar 11 '15 at 13:09
• i've been fighting with an (in-house) tool for preparing web material that invariably doubles backslashes on initial input. (that is, whatever i input and proofread and looks okay, when it gets to the web, every backslash is doubled. so i have to go back and re-edit to remove the bogus ones.) i don't know which is worse -- doubling or dividing by two. either way, it's an inexcusable corruption, mighty unhelpful to the person who's trying to get useful and correct information on a tex-related topic. Mar 11 '15 at 13:35

The linked question has now been fixed as part of a general fix of several thousand similarly affected posts, see

https://tex.meta.stackexchange.com/a/7326

• I noticed this same problem still arising in a separate question: tex.stackexchange.com/a/45660/117534.
– Troy
Jul 13 '17 at 14:08
• @Troy hmm my sql can't be quite right. How did you spot that? Jul 13 '17 at 14:26
• I stumbled upon it (by chance). I was trying to edit it to add an output image.
– Troy
Jul 13 '17 at 14:27
• @Troy thanks for that I fixed my SQL and now sadly there are still four and a half thousand postings left: data.stackexchange.com/tex/query/695037/bug-query-on-markdown Jul 13 '17 at 14:50
• That was fast. I'll help to clear some out!
– Troy
Jul 13 '17 at 14:51
• @Troy since none of these actually show on site, an alternative plan is just hope people notice as they edit, and then occasionally do the previous query of the live html to check none have appeared due to recent edits. Jul 13 '17 at 14:52