Breaking: #101950 - Removed legacy setting 'GFX/processor_allowTemporaryMasksAsPng'

See forge#101950

Description

GFX/processor_allowTemporaryMasksAsPng is a setting that stems from an even older setting called im_mask_temp_ext_gif. This setting was added because generally PNG generation of Image/GraphicsMagick is always faster than generating GIF files, but there were issues with PNG files in earlier versions of ImageMagick 5.

TYPO3 requires newer versions of GraphicsMagick and at least ImageMagick version 6, in which the above reported behaviours couldn't be replicated anymore, obsoleting the need for a non-PNG setting entirely.

The following global settings have no effect anymore and are automatically removed if still in use:

$GLOBALS['TYPO3_CONF_VARS']['GFX']['processor_allowTemporaryMasksAsPng'] (removed)

Impact

Temporarily saved masking images are now saved as PNG files rather than GIF images.

Testing has revealed no visual changes between this setting being turned on or off, with both ImageMagick or GraphicsMagick.

Affected installations

Every instance that already didn't set processor_allowTemporaryMasksAsPng to true.

Migration

The configuration value has been removed without replacement. No migration is necessary.