FIX Use empty array as a fallback for preg_split within DBText summary

[michalkleiner]

If the content is invalid for whatever reason e.g. when instantiating a DBText field to get a summary of text through DBField::create_field('Text', $content)->Summary(10) from a UTF-malformed string, preg_split returns false and the rest of the code expects an array.

This fix ensures an array is always returned even when preg_split fails.

[robbieaverill]

All of these are parts that are immediately expecting iterable results, so LGTM. Thanks!

[sminnee]

The only thing I'd suggest would be a test that fails without this patch, to ensure we don't regress.

[michalkleiner]

Is there anywhere a test already dealing with invalid UTF string that I could look at?

[bergice]

Is there anywhere a test already dealing with invalid UTF string that I could look at?

\SilverStripe\ORM\Tests\DBTextTest::testValidUtf8 seems like a good option.

[dhensby]

I agree a test would be good, but we shouldn't prevent a merge that is clearly a good enhancement just because existing testing doesn't cover a fairly obvious failure case.

[michalkleiner]

Rebased on 4.8 and added a test for DBText->Summary, but Travis fails on version resolution ¯\(ツ)/¯ before it can run it.

[dhensby]

Thanks @michalkleiner - but since of the new tests are failing, are you happy to keep looking into it?

[michalkleiner]

Yep @dhensby, will get it through ;-) The tests were not even running since I targetted 4.8, now they are after a rebase so can finally finish resolving this.

[michalkleiner]

@dhensby all green now ;-)