This change both speeds up specs (less strings to allocate) and helps catch
cases where methods in Discourse are mutating inputs.
Overall we will be migrating everything to use #frozen_string_literal: true
it will take a while, but this is the first and safest move in this direction
This feature ensures optimized images run via pngquant, this results extreme amounts of savings for resized images. Effectively the only impact is that the color palette on small resized images is reduced to 256.
To ensure safety we only apply this optimisation to images smaller than 500k.
This commit also makes a bunch of image specs less fragile.
This also adjusts the algorithm to expect
- 30% saving for JPEG conversion
AND
- Minimum of 75K bytes saved
The reasoning for increase of saving requirements is cause PNG may have been
uploaded unoptimized, 30% saving on PNG is very possible
In the past the filename of the origin was used as the source
for the extension of the file when optimizing on upload.
We now use the actual calculated extension based on upload data.
