EXIF image orientation issue

[tbember]

Description:
Images with EXIF orientation flag can be displayed in wrong orientation.

Steps to reproduce:
Go to the WordPress Media Library screen and upload images 2, 4, 5, 7 (either portrait or landscape) from the repo below - the images should display in wrong orientation.

​https://github.com/recurser/exif-orientation-examples

Cause:
On wp-includes/class-wp-image-editor.php, the function flip() is being called with swapped parameters.

I presume there was probably some confusion around the meaning of $horz and $vert params. Rather than flipping the image horizontally and vertically, respectively, they actually flip the image along the horizontal and vertical axis, respectively, which is the complete opposite behavior. This subject has already been discussed on: #23775.

Proposed solution
Apply the attached patch.

[SergeyBiryukov]

Hi there, welcome to WordPress Trac! Thanks for the ticket and the patch.

The code in question was added in [46202] / #14459, changing the version accordingly.

Moving to 6.0 for investigation.

[mikeschroder]

This came up in a ​bug scrub for 6.0, and I brought it up for discussion / testing in #core-media.

[costdev]

The patch still applies cleanly against trunk. However, as it still needs testing and today is 6.0 RC1, I'm moving this ticket to the 6.1 milestone.

Trac ticket: https://core.trac.wordpress.org/ticket/54937

[adamsilverstein]

The fix looks good here, I verified this corrects the rotation for the test set images.

Core Patch: https://core.trac.wordpress.org/ticket/54937

This PR is only for testing purposes.

[antpb]

In 54265:

Media: Respect EXIF Rotations.

Previously, the logic to determine EXIF rotation information was not providing the correct rotation. This patch respects the information properly by swapping some of the flip() logic on certain rotations.

Props tbember, SergeyBiryukov, costdev, mikeschroder, adamsilverstein.
Fixes #54937.