Fix swapped parent/child sides in patch consolidation merge#153
Merged
Fix swapped parent/child sides in patch consolidation merge#153
Conversation
merge_block_deltas treated the incoming block as the parent and the running result as the child, but blocks are iterated oldest-first, so the running result is the older delta and should be the parent. The swap caused multi-block patches to either silently fall back to a full state TRUNCATE+INSERT (when a merge rule errored) or, for two consecutive updates on the same column, produce a degenerate update with old == new that sparse-encoded into an empty SET clause. Signed-off-by: Lars Erik Wik <lars.erik.wik@northern.tech> Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
merge_block_deltastreated the incoming block as the parent and the running result as the child, but blocks are iterated oldest-first, so the running result is the older delta and should be the parent.The swap caused multi-block patches to either silently fall back to a full state TRUNCATE+INSERT (when a merge rule errored under the swap) or, for two consecutive updates on the same column, produce a degenerate update with
old == newthat sparse-encoded into an empty SET clause:Regression test
test_consecutive_updates_same_column_consolidatereproduces the original report (two consecutive price updates on the same row) and asserts a delta-path patch with the correct final value.