English SEO url updates in promote panel leads to wrong redirects and 404 pages

[rruebner]

Problem

If you change the english SEO url in the promote panel in the frontend there are wrong 301 redirects in the menu entry and the language switcher and possible 404 pages.

Steps to reproduce

• create a new database with language german and with demo data
• install the website_seo module
• activate the developer mode
• go to Settings -> Translations -> Languages and set the "Short code" to "en" for the "English" entry
• go to Website Admin -> Configuration and add "German / Deutsch" as second language and as default language and save
• go to the german contact page in the frontend, open the promote panel, change the SEO url to kontakt and save: it is all correct so far
• now open the promote panel again on german contact page, change the language to english in the promote panel, after that change the SEO url to contact and save

Current behaviour

• go to the german home page and hover the mouse over the contact menu entry in the top right corner: you see /kontakt -> this is fine
• go to the german contact page and hover the mouse over the english language entry in the top left corner: you see /en/kontakt -> this is wrong, it should be /en/contact
• go to the english home page and hover the mouse over the contact menu entry in the top right corner: you see /en/kontakt -> this is wrong, it should be /en/contact
• go to the english contact page and hover the mouse over the german language entry in the top left corner: you see /contact -> this is wrong, it should be /kontakt
• go to the german contact page and click on the english language entry in the top left corner: you will be forwarded from /en/kontakt to /en/contact (the redirect itself is fine but it shouldn't be used here, like described in the point above)
• from the english contact page click on the german language entry in the top left corner: you will be forwarded to /contact which leads to a 404 page

Expected behaviour

• the redirects should be created but they shouldn't be used in the menu entries and language switcher
• there should be no 404 pages caused by wrong language entries

[jholze]

@fshahy can you do this ticket ? would be helpful, because we want to deploy the first version to OCA as soon as possible

@rruebner in steps to reproduce (6th step) when trying to change SEO URL of kontakt page and save, the window does not save and stays open. I am using latest V9 and tried with Firefox and Chrome on Ubuntu.
(It happens when I create a DB with demo data, in a DB without demo data it is ok.)