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Due to how pg_size_pretty(bigint) was implemented, it's possible that when
given a negative number of bytes that the returning value would not match
the equivalent positive return value when given the equivalent positive
number of bytes. This was due to two separate issues.
1. The function used bit shifting to convert the number of bytes into
larger units. The rounding performed by bit shifting is not the same as
dividing. For example -3 >> 1 = -2, but -3 / 2 = -1. These two
operations are only equivalent with positive numbers.
2. The half_rounded() macro rounded towards positive infinity. This meant
that negative numbers rounded towards zero and positive numbers rounded
away from zero.
Here we fix #1 by dividing the values instead of bit shifting. We fix #2
by adjusting the half_rounded macro always to round away from zero.
Additionally, adjust the pg_size_pretty(numeric) function to be more
explicit that it's using division rather than bit shifting. A casual
observer might have believed bit shifting was used due to a static
function being named numeric_shift_right. However, that function was
calculating the divisor from the number of bits and performed division.
Here we make that more clear. This change is just cosmetic and does not
affect the return value of the numeric version of the function.
Here we also add a set of regression tests both versions of
pg_size_pretty() which test the values directly before and after the
function switches to the next unit.
This bug was introduced in
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| authentication | ||
| examples | ||
| isolation | ||
| kerberos | ||
| ldap | ||
| locale | ||
| mb | ||
| modules | ||
| perl | ||
| recovery | ||
| regress | ||
| ssl | ||
| subscription | ||
| thread | ||
| Makefile | ||
| README | ||
PostgreSQL tests ================ This directory contains a variety of test infrastructure as well as some of the tests in PostgreSQL. Not all tests are here -- in particular, there are more in individual contrib/ modules and in src/bin. Not all these tests get run by "make check". Check src/test/Makefile to see which tests get run automatically. authentication/ Tests for authentication examples/ Demonstration programs for libpq that double as regression tests via "make check" isolation/ Tests for concurrent behavior at the SQL level locale/ Sanity checks for locale data, encodings, etc mb/ Tests for multibyte encoding (UTF-8) support modules/ Extensions used only or mainly for test purposes, generally not suitable for installing in production databases perl/ Infrastructure for Perl-based TAP tests recovery/ Test suite for recovery and replication regress/ PostgreSQL's main regression test suite, pg_regress ssl/ Tests to exercise and verify SSL certificate handling subscription/ Tests for logical replication thread/ A thread-safety-testing utility used by configure