I agree that for template development it would be very helpful to have the full template + file URL available.

At previous versions this URL could simply be copied from the browser to hand the link to other designers for checking certain files of a certain template.
That was always very helpful.
Maybe we could simply link the file name top left saying "Editing file 'startpage.pstpl'"?

I was just working with the theme editor, and selected a theme that I wanted to delete, but the previous theme I had selected was deleted instead of the currently selected one... not fun!

Carsten spent a lot of time to move everything from GET to POST.

But I agree in a point : Post should be use only to post datas, and get should be use when getting datas, so you can share the URL to get the very same page.

Mazi give a good idea : the line at top "Editing file 'startpage.pstpl'" can be link with GET.

@all, I have raised the priority to "high" because this issue leads to existing custom template details getting overwritten. That is quite painful.

I have experienced this issue when i was switching between different themes to copy code from one theme to another. It looks like the theme changes, but actions sometimes affect a previous selected theme. One time i saved changes in one theme, and they got applied to another theme (it basically overwrote the code of a .pstpl of another theme) - hope this info helps!

RE "Carsten spent a lot of time to move everything from GET to POST."

Do you know where I can find the related commit?

Fix committed to master branch: http://bugs.limesurvey.org/plugin.php?page=Source/view&id=19412

This was no a single commit but a series of commits by Louis and me.
We found a more reliable way now.

Fix committed to master branch: http://bugs.limesurvey.org/plugin.php?page=Source/view&id=19413

Version 2.50 Build 160613 released