[lomkiri]

TL;DR :
Would it be possible to add a warning when exiting the regex-function editor (on "esc" key) when the state of the editor is "dirty" ?

This dialog could have a checkbox "Ask next time" so if it perturbs someone, it's easy to get rid of it.

Tip : I use vim so it became a reflex for me to use "esc" before any operation.

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Why I' asking this :

Regex-function is a powerful recourse. I use it a lot. I'm even working on a plugin (together with a friend) that uses them quite a few (to be published in some months).

When the code of the function is not trivial, I write it in vim, then I copy it in the function-editor of calibre. When I modify it in the function-editor to correct typos or bugs, I often use, by mistake, "esc", that in vim restores the "normal-mode". But, in calibre, ... it exits the modified function without warning and without saving, so I loose all the modifications (sometime extensive).

TIA