Regex lookups should not fail on null/None and non-string values on SQLite

[noirbizarre]

The user function provided to do the regex lookup is buggy for two cases:

• raise an exception when the value is None (null in databse)
• raise an exception when the value is not a string

I provided a pull request fixing these issues: ​https://github.com/django/django/pull/1043

[Anssi Kääriäinen]

Ensuring that all databases behave the same way whenever this is possible is a good idea.

[Tim Graham <timograham@…>]

In 64041f0e6e7a773574d7cde978d16305200004ea:

Fixed #20462 - Fixed sqlite regex lookups for null values and non-string fields.

[Tim Graham <timograham@…>]

In 92c49d6f01700961698eb3d79fd393d673cee219:

Revert "Fixed #20462 - Fixed sqlite regex lookups for null values and non-string fields."

This reverts commit 64041f0e6e7a773574d7cde978d16305200004ea.

lookup.tests.LookupTests.test_regex_non_string fails under Postgres.
We should also try to rewrite the test using an existing model.

[amclark7]

Added a pull request for fixing this issue: ​https://github.com/django/django/pull/1306

This is only a minor change compared to the original patch provided by noirbizarre.

[Tim Graham <timograham@…>]

In 273dc550a4eccdad958541f456332312b3369504:

Fixed #20462 -- null/non-string regex lookups are now consistent

Thanks to noirbizarre for the report and initial patch.

[Tim Graham]

As pointed out in IRC by loic84, the str() cast added in django/db/backends/sqlite3/base.py should probably be something like force_text to properly handle unicode.

[loic84]

PR ​https://github.com/django/django/pull/1308

[Loic Bistuer <loic.bistuer@…>]

In a9ea7d8c708c8265cccc17f23c62b2268d9e94f8:

Fixed #20462 - Replaced the str() cast introduced in 273dc55 by force_text()

[Tim Graham <timograham@…>]

In b6a87f5c93efa5192433be1e45fc4e79d54efdc7:

Merge pull request #1308 from loic/ticket20462

Fixed #20462 - Replaced the str() cast introduced in 273dc55 by force_text()