postgresql/src/test
David Rowley 45bad6a398 Fix incorrect return value in pg_size_pretty(bigint)
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 8a1fab36a. Prior to that negative values were
always displayed in bytes.

Author: Dean Rasheed, David Rowley
Discussion: https://postgr.es/m/CAEZATCXnNW4HsmZnxhfezR5FuiGgp+mkY4AzcL5eRGO4fuadWg@mail.gmail.com
Backpatch-through: 9.6, where the bug was introduced.
2021-07-09 14:05:05 +12:00
..
authentication Make new authentication test case more robust. 2020-09-04 21:01:59 -04:00
examples Client-side fixes for delayed NOTIFY receipt. 2018-10-19 22:22:57 -04:00
isolation Remove memory leaks in isolationtester. 2021-06-27 12:45:04 -04:00
kerberos Fix potential rare failure in the kerberos TAP tests 2021-04-07 19:59:41 +09:00
ldap Fix rare failure in LDAP tests. 2020-08-03 12:48:11 +12:00
locale Add a temp-install prerequisite to "check"-like targets not having one. 2017-11-05 18:51:08 -08:00
mb Fix MB regression tests for WAL-logging of hash indexes. 2017-03-15 07:25:36 -04:00
modules Improve display of query results in isolation tests. 2021-06-23 11:12:31 -04:00
perl Ignore more environment variables in pg_regress.c 2021-06-13 20:07:54 +09:00
recovery Fix prove_installcheck to use correct paths when used with PGXS 2021-07-01 08:47:21 -04:00
regress Fix incorrect return value in pg_size_pretty(bigint) 2021-07-09 14:05:05 +12:00
ssl Allow SSL TAP tests to run on Windows 2019-09-29 17:50:44 -04:00
subscription Fix deadlock for multiple replicating truncates of the same table. 2021-05-21 08:31:10 +05:30
thread Update copyright for 2018 2018-01-02 23:30:12 -05:00
Makefile Revert "Allow on-line enabling and disabling of data checksums" 2018-04-09 19:03:42 +02:00
README Add TAP tests for password-based authentication methods. 2017-03-17 11:34:16 +02:00

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