Fix left outer merge join wrong results with residual filters - #11358
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Fixes two defects in mergeJoinKvIter for left outer merge joins whose key runs contain duplicates and whose join condition carries a residual (non-merge-key) filter: 1. matchedLeft was overwritten on every pairing (matchedLeft = ok), so a later pairing in the same key run that failed the residual filter erased an earlier success, and the key-run transition then emitted a spurious null-extended row for a left row that had already matched. Now matchedLeft is only ever set within a run (matchedLeft || ok); the run-transition reset remains the sole reset point. 2. When the left iterator hit io.EOF while advancing past a completed left row in the match loop, the error was returned immediately, dropping the null-extended row owed to a final unmatched left row. Now the null-extended row for tmpKey is emitted before surfacing EOF, mirroring the compare loop's oldLeftKey handling. Both defects surface as wrong LEFT JOIN ... IS NULL anti-join results (phantom and missing orphans). Regression tests included; the identical plan executed by the GMS memory engine already returned correct results. Fixes #11350 Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01VpTxMfzCXHoM8ojJn5aQiv
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@angelamayxie DOLT
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@angelamayxie DOLT
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@angelamayxie DOLT
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angelamayxie
marked this pull request as ready for review
July 29, 2026 00:04
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jycor
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Jul 29, 2026
[auto-bump] [no-release-notes] dependency by angelamayxie
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@angelamayxie DOLT
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Tests added in dolthub/go-mysql-server#3655
Fixes #11350
Based on #11351