Image caption gets removed when editing image dimensions.

[JanJaapKempenaar]

When editing an image placed into a post in a certain way, the caption of the image is removed.

Steps to reproduce:

1. Edit a post that contains an included image.
2. Click the edit options icon when selecting the image.
3. Go to the advanced image settings(make sure the image does have a caption).
4. Empty the width field.
5. Press the submit button.

-> The caption of the image is set empty.

Remarks,
In my case only leaving the width input field blank caused this issue.

This is intentional, but I don't understand why. Perhaps another dev can shed some light on this.

editimage.dev.js line 366

if ( f.img_cap.value != '' && f.width.value != '' ) {
	do_caption = 1;
	img_class = img_class.replace( /align[^ "']+\s?/gi, '' );
}

Replying to kurtpayne:

To be able to style the caption wrap div, we need the image width. The bug here is that we allow the image width field to be empty. Probably should populate it with the actual width when left empty and clicking submit.