I encountered this issue a few weeks ago, when tried to embed nested inline-editor with no defined height (i.e. .cm-editor {height: auto}). Here is an example
While typing/erasing a new character from the end it changes size randomly, but if there is one left it stays stable.
I tracked DOM changes and did not find any odd activity. Looks like it is enough to toggle (on and off) any class inside cm-scroller to stabilize the size of an editor.
Applying overflow: overlay also did not help.
If the text field was pre-rendered (no changes from the user happened) it always renders correctly.
I’m able to reproduce it in Safari, but only if it is set to always showing scrollbars. I think most have it set to only show the scrollbars when scrolling, with a trackpad. I’ve observed that a lot of websites don’t look good when the option is set like this.
height: 45px fixes it for me, but makes it look different. Just an example.
Thank you @benatkin, I tried my best and just nothing was willing to work. Cool
I have finally uploaded all experiments with nested editors to a package and will try to apply your trick on this.
