set err to nil after ReadFull returns io.EOF#245
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When source size is multiple of block size, final io.ReadFull returns (0, io.EOF) `err` only cleared by `w.write` when `rn > 0` This broke io.Copy which uses dst.(io.ReaderFrom) shortcut, propagating io.EOF to caller
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Alternatively not using implicit return variables here could be used. Personally I configure linting to prevent use of that feature |
serprex
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Apr 29, 2026
| @@ -222,6 +222,7 @@ func (w *Writer) ReadFrom(r io.Reader) (n int64, err error) { | |||
| switch err { | |||
| case nil: | |||
| case io.EOF, io.ErrUnexpectedEOF: // read may be partial | |||
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imo UnexpectedEOF should not be ignored, but that's a larger change of behavior predating recent regression
serprex
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Apr 30, 2026
bumped in #2233 this regressed gp/cloudberry due to pierrec/lz4#245
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debebantur
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Jun 1, 2026
4.1.27 contains both pierrec/lz4#240 & pierrec/lz4#245 which are relevant when we're often compressing files with sizes that are a power of 2
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When source size is multiple of block size, final io.ReadFull returns (0, io.EOF)
erronly cleared byw.writewhenrn > 0This broke
io.Copywhich usesdst.(io.ReaderFrom)shortcut, propagatingio.EOFto callerRegression from #240