9fafa413ac
LogicalTapeFreeze() may write out its first block when it is dirty but not full, and then immediately read the first block back in from its BufFile as a BLCKSZ-width block. This can only occur in rare cases where very few tuples were written out, which is currently only possible with parallel external tuplesorts. To avoid valgrind complaints, tell it to treat the tail of logtape.c's buffer as defined. Commit 9da0cc35284bdbe8d442d732963303ff0e0a40bc exposed this problem but did not create it. LogicalTapeFreeze() has always tended to write out some amount of garbage bytes, but previously never wrote less than one block of data in total, so the problem was masked. Per buildfarm members lousyjack and skink. Peter Geoghegan, based on a suggestion from Tom Lane and me. Some comment revisions by me.
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/.