round palette bit depth up for png and gif colours - #4569
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This PR contains the following updates: | Package | Change | [Age](https://docs.renovatebot.com/merge-confidence/) | [Confidence](https://docs.renovatebot.com/merge-confidence/) | |---|---|---|---| | [sharp](https://sharp.pixelplumbing.com) ([source](https://github.com/lovell/sharp), [changelog](https://github.com/lovell/sharp/blob/main/docs/src/content/docs/changelog.md)) | [`0.35.3` → `0.35.4`](https://renovatebot.com/diffs/npm/sharp/0.35.3/0.35.4) |  |  | --- ### Release Notes <details> <summary>lovell/sharp (sharp)</summary> ### [`v0.35.4`](https://github.com/lovell/sharp/releases/tag/v0.35.4) [Compare Source](lovell/sharp@v0.35.3...v0.35.4) <https://github.com/lovell/sharp-libvips/releases/tag/v1.3.3> - Bound resize dimensions to coordinate limit. - Bound composite left and top to coordinate limit. [#​4564](lovell/sharp#4564) [@​metsw24-max](https://github.com/metsw24-max) - Round palette bit depth up for png and gif colours. [#​4569](lovell/sharp#4569) [@​metsw24-max](https://github.com/metsw24-max) - Ensure tiff.subifd input option is used. [#​4572](lovell/sharp#4572) [@​metsw24-max](https://github.com/metsw24-max) - Ensure `info.pages` is correct when limiting input page range. [#​4578](lovell/sharp#4578) [@​metsw24-max](https://github.com/metsw24-max) - Improve support for input Streams finishing before output is requested. [#​4584](lovell/sharp#4584) [@​Jaybhade](https://github.com/Jaybhade) </details> --- ### Configuration 📅 **Schedule**: (UTC) - Branch creation - At any time (no schedule defined) - Automerge - At any time (no schedule defined) 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box --- This PR has been generated by [Mend Renovate CLI](https://github.com/renovatebot/renovate). <!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0NC41MC4zIiwidXBkYXRlZEluVmVyIjoiNDQuNTAuMyIsInRhcmdldEJyYW5jaCI6Im1haW4iLCJsYWJlbHMiOltdfQ==-->
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Palette bit depth rounds down instead of up
bitdepthFromColourCountmaps thecoloursoption to a PNG/GIF palette bit depth of 1, 2, 4 or 8, but it rounds the required bit count down to the nearest power of two, so a value needing 5 to 8 bits is capped at 4 and one needing 3 bits at 2.png({ colours: 128 })andgif({ colours: 100 })therefore emit a 16-entry palette, andcolours: 8a 4-entry one, quietly discarding colours the caller asked to keep (visible via metadatabitsPerSample). Rounding up instead keeps the stored depth one of 1/2/4/8 while making it large enough to hold the requested count.The reduced-colours GIF size test happened to depend on the old behaviour, as
colours: 128only shrank the file because it collapsed to 16 entries, so it now usescolours: 16which still exercises a genuinely smaller palette. Added a PNG regression test asserting the written bit depth can represent the requested number of colours.