bug: Fix decimal.InvalidOperation on /system for some PG versions

[richid]

Description

In #2730 the /system page was improved to warn the user if the version of Postgres they are using is out of date and should be updated. The current code attempts to determine the major versions by replacing 00 with . and then converting to a Decimal. Unfortunately, it appears the only value this method does not work for are initial releases of major versions, like 16.0.0.

For reference, either Postgres or the PsyCog driver represents the semver values but without the dots, so 16.0.0 becomes 1600000.

This change removes the string replace and Decimal conversion in favor of using the divmod() function. In this application it will return a tuple with the first element being the major version of Postgres. This is then used as before to compare against deprecated versions.

Versions

Postgres

=# SELECT version();
                                              version
------------------------------------------------------------------------------------------------------
PostgreSQL 16.0 (Debian 16.0-1.pgdg120+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 12.2.0-14) 12.2.0, 64-bit
(1 row)

Tandoor

Tandoor (HEAD) - 1.5.14

commit a626bda1ab400efc2f6a5f9de3c307f857ea7026
Author: vabene1111 
Date:   Tue Mar 5 14:06:56 2024 +0100

    Merge branch 'develop'

Reproduction

>>> Decimal("160000".replace('00', '.'))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
decimal.InvalidOperation: [<class 'decimal.ConversionSyntax'>]
>>> Decimal("160001".replace('00', '.'))
Decimal('16.01')

Testing

Manually testing with the following values and confirmed the /system page displayed the info/warning/ok notices as expected.

postgres_ver = divmod(160000, 10000)[0]
postgres_ver = divmod(160001, 10000)[0]
postgres_ver = divmod(150000, 10000)[0]
postgres_ver = divmod(140000, 10000)[0]
postgres_ver = divmod(120000, 10000)[0]

[CLAassistant]

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[vabene1111]

awesome, thank you for fixing this!

[blknight88]

wondering if this caused a new issue as now I get a code 500 on the system page after updating to 1.5.15 and the "python3 version.py" now gets "fatal: no tag exactly matches" which worked before.