Images not removed upon restore when IMAGE_EDIT_OVERWRITE true

[bradt]

With IMAGE_EDIT_OVERWRITE set to true, image edit files are removed when the original image is restored. But in certain cases, leftover image edit files remain.

Steps to reproduce:

1. Add define( 'IMAGE_EDIT_OVERWRITE', true ); to your wp-config.php
2. Upload an image
3. Crop it and save
4. Crop it and save again

You'll notice that the second crop overwrote the 150x150 intermediate image, created some new intermedia images, and left some intermediate images from the first crop behind. Now if you restore the original image, the images created by the second crop are removed, but the leftover images from the first crop remain.

It should probably remove the images from the first crop when you do the second crop.

[mtekk]

I was able to reproduce this quite easily. A little more background on this, it appears to only occur when the aspect ratio of the crops are not the same (hence the 150x150 thumbnail getting overwritten but nothing else is). When that happens, the scaled images will have multiple copies for a specific limiting dimension.

Keep the related ticket #32302 in mind when approaching a solution.

[bradt]

Added a unit test.

[chriscct7]

Since the $meta is being pulled via a helper function from a piece of post_meta, I've added checks to ensure that expected indices exist, as plugins could if they wanted to change the expected results.

This looks good otherwise.

[chriscct7]

Adds some checks for safety when trying to access indices of an array coming from post_meta

[chriscct7]

Ignore these. Me and nacin are testing a bug in trac at wceu.

[kirasong]

I'll handle the last review for commit.

[kirasong]

Clean up; use existing stored dirname, rather than extracting for each size.

[kirasong]

In 32171.3.diff​:
Small clean up; use existing stored dirname, rather than extracting for each size.

[kirasong]

In 38113:

Media: Clean up prior image edits if IMAGE_EDIT_OVERWRITE is true.

When IMAGE_EDIT_OVERWRITE is set to true, edited image files are
supposed to be deleted when an image is restored to the original.

However, when an image was edited more than once, and then restored,
files created during previous edits were left behind.

Fixes this behavior by updating wp_save_image() to clean up
leftover images after each edit when IMAGE_EDIT_OVERWRITE is true.

Props bradt, chriscct7, joemcgill.
Fixes #32171.

[ocean90]

In 38139:

Docs: Fix minor formatting issue for a comment added in [38113].

See #32171.