Opening the same image twice and losing data

[grofaty]

Latest Pinta 1.7.0.204 downloaded from forge.pinta-project.com on Ubuntu 14.04 LTS.

1. Open existing image like: sample.png.
2. Make some modifications on it like Adjustments | Black & White (it isn't important what kind of modification you perform).
3. Open button from toolbar and open the same! sample.png image. It opens up without a problem. But in my humble opinion this is dangerous because it can lead to all sort of problems.
4. Click on first tab to get image from step 1. You can see on tab instead of "x" it is "o" which indicates image was changed. Click Save button from toolbar.
5. But now another problem in second tab where original image is there is no indication that original file saved on disk is different that image in Pinta's second tab. So executing File | Quit and you lose original image.

This is how I lost original image because I was convinced that image did not change.

In my humble opinion one of three options should apply:
a) Pinta should not allow the same image to be opened more then one time (extra strong solution, but maybe little bit limiting),
b) recognize that image on disk was changed before closing it down (this is probably going to be hard like checking the hash value of image or similar),
c) when the image is opened for the second time warn that image with the same name (and path) is already opened in Pinta and automatically set new name to sample-1.png and mark this new file as unsaved (probably simplest to do, because only check of image path is required). The warning should look like: "Image 'sample.png' is already opened. Do you want to reopen it with new name 'sample-1.png'?". Buttons: Open, Cancel.