Hugo 0.37: Preserve PNG Colour Palette

The main item in Hugo 0.37 is that we now properly preserve the colour palette when processing PNG images. We got reports from users experiencing their PNG images getting bigger in file size when scaled down. Now, if you, as an example, start out with a carefully chosen 8 bit colour palette (i.e. PNG-8), this is now what you will end up with. A special thanks to @aitva for doing the investigative work finding a proper fix for this issue.

This release represents 40 contributions by 5 contributors to the main Hugo code base.

@bep leads the Hugo development with a significant amount of contributions, but also a big shoutout to @vassudanagunta, @kaushalmodi, and @curttimson for their ongoing contributions.

And as always a big thanks to @digitalcraftsman for his relentless work on keeping the documentation and the themes site in pristine condition.

Many have also been busy writing and fixing the documentation in hugoDocs, which has received 24 contributions by 8 contributors. A special thanks to @bep, @4RU, @kaushalmodi, and @mitchchn for their work on the documentation site.

Hugo now has:

• 23649+ stars
• 447+ contributors
• 197+ themes

Notes

• Hugo will now convert non-string YAML map keys to string. See #4393 for more information. You will get a WARNING in the console if you are touched by this.
• We have improved the PNG processing, and have incremented the version numbers on the URL for the processed PNG image. This will just work, but you may want to run hugo --gc to clean up some old stale images in the resource cache.

Enhancements

Templates

• Add template func for TOML/JSON/YAML docs examples conversion. This is mainly motivated by the needs of the Hugo docs site. d382502d @bep #4389

Core

• Refactor tests for JSON, YAML and TOML equivalency, add coverage 82eefded @vassudanagunta
• Re-enable YAML data tests disabled in f554503f e1728349 @vassudanagunta

Other

• Preserve color palette for PNG images 799c654b @bep #4416
• Use Floyd-Steinberg dithering for PNGs 13ea1e7c @bep #4453
• Make ge, le etc. work with the Hugo Version number 0602135f @bep #4443
• Update dependencies eaf573a2 @bep #4418
• Update to Go 1.10 (!) Take 2 a3f26e56 @bep
• Update to Go 1.10 (!) ff10c15a @bep
• Add WARNING for integer YAML keys 0816a97a @bep #4393
• Tune stringifyMapKeys 10a917df @bep
• Rename stringifyYAMLMapKeys to stringifyMapKeys d4beef0d @bep
• Add benchmarks for stringifyYAMLMapKeys 51213e0b @bep
• Add support for YAML array data files 1fa24177 @vassudanagunta #3890
• Account for array type data in data dir merge/override logic bb549a0d @vassudanagunta #4366
• Add “target” and “rel” parameters to figure shortcode 2e95ec68 @kaushalmodi
• image" property, not “twitter:image:src” 76d38d5e @kaushalmodi

Fixes

Core

• Continue GitInfo lookup on error e9750d83 @bep
• Fix paginator URL for sections with URL in front matter 9f740b37 @bep #4415

Other

• Fix bug in Site.assembleSections method 00868081 @vassudanagunta #4447
• Update Blackfriday to fix footnote HTML5 validation error 492fea7c @bep #4433
• Fix YAML maps key type 16a5c745 @dmgawel #2441
• Remove ERROR on missing baseURL 55bd46a6 @bep #4397