Tinymce allows you to resize an image larger than the original

[tellyworth]

1. Insert a Medium image into your post at 300 pixels wide.

2. In the visual editor, click the image and then drag its bottom-right anchor to the right, to make it wider than 300 pixels.

Voila: instant rubbish looking image.

Expected: TinyMCE should check the actual size of the image and use the width and height as maximum bounds for resizing.

I disagree - limiting the size of an image to a maximum of it's original resolution places limitations into a system that need not be there.

Some users may want to hyper-scale their image. If we applied a fix along the lines suggested here we'd have another bug reported stating that users can't upscale images and then we'd have to implement and over ride to workaround.

Or am I being unreasonable in expecting that users of software apply some common sense?

Totally agree with MattyRob. It could be an option in the admin, but even that would confuse users. It would be something like "shutdown my machine when I press Enter" and then novice users would turn it on.

If you want to limit user preference than create a plugin or if you can't create one, then create a new ticket.

TinyMCE issues should also be sent to the TinyMCE tracker.