Redmine

See this plugin https://github.com/ries-tech/sidebar_hide
It adds ability to hide the sidebar.

I know that sidebar_hide plugin does a good job! I think this is something shouldn't be done through plugins.

Many themes are simply not compatible with the the plug-in. Unfortunately, by digging up you realize this is is neither a plug-in's own issue as such because many themes have their own peculiar problems (and default theme works) on the other hand - most themes works perfectly except this side bar features!

So I strongly vote NOT to close this feature and must have this feature in the core - as soon as possible.

Yes I would agree Dipan.
There are many different types of request regarding a collapsible sidebar or a better sidebar customization.

I would prefer to integrate a little script for the collapsible sidebar.
This could close many issues and this function would come out of the box with Redmine.

I added a little Javascript in my theme to solve this problem for me with some cookie. But I'm sure, that this would be better to save the collapsed state in the database.

I would strongly request if we can include this as part of 2.4?