fix: Handle negative block counts in Avro map/header parsing #6
Conversation
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
Per the Avro specification, when reading maps (and arrays), a negative block count indicates that the absolute value should be used as the count, and a byte size follows for fast skipping. Previously, the code cast the signed zigzag value directly to usize, causing a negative value like -8 to become 18,446,744,073,709,551,608 on 64-bit systems, triggering a hash table capacity overflow panic. Also skips parsing of 'default' field values since the current implementation incorrectly expects them to be Schema types rather than actual default values. Fixes reading of Apache Iceberg manifest files which use this encoding.
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Outdated suggestions cannot be applied.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.
Per the Avro specification, when reading maps (and arrays), a negative block count indicates that the absolute value should be used as the count, and a byte size follows for fast skipping.
Previously, the code cast the signed zigzag value directly to usize, causing a negative value like -8 to become 18,446,744,073,709,551,608 on 64-bit systems, triggering a hash table capacity overflow panic.
Also skips parsing of 'default' field values since the current implementation incorrectly expects them to be Schema types rather than actual default values.
Fixes reading of Apache Iceberg manifest files which use this encoding.