Backport of "Revert and properly repair "jpegdec: only allow conversions from RGB"" into 1.20
Backport of !1687 (merged) "Revert and properly repair "jpegdec: only allow conversions from RGB"".
Commits:
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Backport of !1687 (merged) "Revert and properly repair "jpegdec: only allow conversions from RGB"".
Commits: