Refuse a version chain that leads back into itself - #1262
Merged
Merged
Conversation
#allVersionsAt: follows previousVersionPosition until it reaches zero and keeps every version it passes. A chain that returns to a position it has already been at therefore never returns, and the collection grows until the image is gone - which is what a database in the estate did to whichever process tried to back it up, for four months, without an error anywhere. The walk now remembers where it has been and signals SoilDatabaseIsInconsistent when it arrives there again, naming the object and the position. One damaged object then costs its own database rather than the process reading it. Only this walker is guarded. #basicAt:version: and #at:version: follow the same links but stop at the first version they can use, so they circle only when asked for a version the cycle does not contain; this one follows the chain to its end whatever it finds. Co-Authored-By: Claude Opus 5 (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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
#allVersionsAt: follows previousVersionPosition until it reaches zero and keeps every version it passes. A chain that returns to a position it has already been at therefore never returns, and the collection grows until the image is gone - which is what a database in the estate did to whichever process tried to back it up, for four months, without an error anywhere.
The walk now remembers where it has been and signals SoilDatabaseIsInconsistent when it arrives there again, naming the object and the position. One damaged object then costs its own database rather than the process reading it.
Only this walker is guarded. #basicAt:version: and #at:version: follow the same links but stop at the first version they can use, so they circle only when asked for a version the cycle does not contain; this one follows the chain to its end whatever it finds.