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The pg_dump Compressor API has three basic callbacks - Allocate, Write and End. The gzip implementation (since e9960732a) wrongly assumed the Write function would always be called, and deferred the initialization of the internal compression system until the first such call. But when there's no data to compress (e.g. for empty LO), this would result in not finalizing the compression state (because it was not actually initialized), producing invalid dump. Fixed by initializing the internal compression system in the Allocate call, whenever the caller provides the Write. For decompression the state is not needed, so we leave the private_data member unpopulated. Introduces a pg_dump TAP test compressing an empty large object. This also rearranges the functions to their original order, to make diffs against older code simpler to understand. Finally, replace an unreachable pg_fatal() with a simple assert check. Reported-by: Justin Pryzby Author: Justin Pryzby, Georgios Kokolatos Reviewed-by: Georgios Kokolatos, Tomas Vondra https://postgr.es/m/20230228235834.GC30529%40telsasoft.com
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download/ See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.