gh-155004: Fix iconv error handlers in a non-initial shift state - #155005
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serhiy-storchaka wants to merge 3 commits into
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gh-155004: Fix iconv error handlers in a non-initial shift state#155005serhiy-storchaka wants to merge 3 commits into
serhiy-storchaka wants to merge 3 commits into
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The replacement bytes are copied to the output as they are, so the output has to be back in the initial shift state first. Otherwise, in a stateful encoding such as ISO-2022-CN, they are read back as encoded data. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
GNU libiconv resolves ISO-2022-CN-EXT but rejects U+4E2D, so probing the character must not fail the test. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
An iconv() which substitutes an unencodable character instead of failing leaves the shift state, and the substitute is then dropped from the output. The descriptor and the output disagree after that, so the replacement bytes are written in a non-initial shift state. Seen with citrus iconv (FreeBSD: ISO-2022-KR and ISO-2022-CN) and libiconv (macOS: ISO-2022-JP). Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
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The bytes an error handler returns are copied to the output as they are, so the output has to be back in the initial shift state first. It was reset only after the replacement, and with a NULL output buffer, so the closing sequence was never written and the replacement was read back as encoded data.
iconv_reset_shift_state()flushes into the output before the replacement is copied, and only when there is something to copy.iconv:ISO-2022-JPnow matchesiso2022_jpbyte for byte with all four error handlers.Encoding
<char>😀<char>and decoding it back was broken for 146 (encoding, handler) pairs of the 1180 encodingsiconv -llists here, and for none now. The test fails without the change.The iconv codecs are new in 3.16, so there is no NEWS entry.