[RTM] Fix incompatibilities with PCRE 8.32 in the BackportedTranslator class

[plorenz-etes]

Due to a regression in PCRE 8.32 there is a problem using the translator on systems using this version of the library. Some regular expressions can't be parsed which breaks functionality. As a result, e.g. using MetaModels isn't possible because every translation returned has the value 'Array'.

In Contao 4.5, the Translator class was introduced and ran into this problem: contao/contao#886
Since the BackportedTranslator class in this project uses parts of the code from the original Contao Translator class, I think the changes made here to Translator.php should also be made to the BackportedTranslator class: contao/contao#916

Changing these two lines in a test installation environment fixes the problem instantly for me.

[baumannsven]

@plorenz-etes Can you post the translation to use? So we can wrote a test for this problem.

[plorenz-etes]

@baumannsven It basically happens with any translation. The following code will be executed when looking up a translation (BackportedTranslator.php lines 128/129):

preg_match_all('/(?:\\\\[\\\\.]|[^.])++/', $id, $matches);
$parts = preg_replace('/\\\\([\\\\.])/', '$1', $matches[0]);

Since those regular expressions aren't correct for PCRE 8.32, they can't be compiled and thus, the function getFromGlobals() doesn't return a string but rather the complete language array $_GLOBALS['TL_LANG'].

[discordier]

IMO the lines from Contao core can be used along the corresponding unit tests, see commit contao/contao@75c5d8c

[baumannsven]

@discordier Thanks.

[plorenz-etes]

Hi, sorry to ask but since we've got a customer running into this problem - can you tell whether this PR will make it into the next release?

[discordier]

It will as long as the tests are ported as well and the build runs successfully.

Sadly no one of our team has currently the time to port them over, so it would be nice if you could update your PR.

As soon all is green, we will be happy to merge.

[zonky2]

@plorenz-etes please add your name and email as author - see check in travis...

[plorenz-etes]

@zonky2 Thank you for the reminder - I have added the requested author line.

[zonky2]

thx!

[discordier]

The tests are still missing?

[discordier]

Tests still missing, therefore still a NACK from me.