Fix adding a new color when image palette has missing background or transparency index#9799

radarhere merged 3 commits into

python-pillow:mainpython-pillow/Pillow:mainfrom

chuenchen309:fix/imagepalette-getcolor-special-skip-indexchuenchen309/Pillow:fix/imagepalette-getcolor-special-skip-indexCopy head branch name to clipboard