[imp] Message content not displayed after upgrade to PHP 7.3

[Arjen de Korte]

Citeren Michael J Rubinsky <mrubinsk at horde.org>:

> Quoting Arjen de Korte <build+horde at de-korte.org>:
>
>> Citeren Arjen de Korte <build+horde at de-korte.org>:
>>
>>> Citeren Arjen de Korte <build+horde at de-korte.org>:
>>>
>>>> Just a heads-up for those that what to upgrade to PHP 7.3: it  
>>>> seems like there are some incompatibilities with Horde (master)  
>>>> in handling regular expressions.
>>>>
>>>> Some (but not all) messages will not display content.
>>
>> It looks like HTML mail is displayed correctly and text-only ones don't.
>>
>>>> The following is logged for each message:
>>>>
>>>> 2018-12-25T12:47:27+01:00 WARN: horde [imp] PHP ERROR:  
>>>> preg_replace_callback(
>>>> ): Compilation failed: invalid range in character class at offset  
>>>> 68 [pid 207
>>>> 6 on line 99 of "/usr/share/php7/PEAR/Horde/Text/Filter.php"]
>>>> 2018-12-25T12:47:27+01:00 WARN: horde [imp] PHP ERROR:  
>>>> preg_replace_callback(
>>>> ): Compilation failed: invalid range in character class at offset  
>>>> 649 [pid 20
>>>> 76 on line 99 of "/usr/share/php7/PEAR/Horde/Text/Filter.php"]
>>>>
>>>> This may be due to the stricter interpretation of character  
>>>> ranges in classes.
>>>
>>> Note that the message content is available. I can reply to such a  
>>> message (like the one quoted above) just fine. So the trouble  
>>> seems to be in rendering messages, rather than grabbing them from  
>>> the IMAP server.
>
> Any chance you can get a stack trace to see where the regexp is  
> coming from? I can't reproduce this on a fresh VM I spun up with php  
> 7.3 and current git master.
>
> I did find some regexps that needed to be fixed, but I dont' think  
> those are called when just displaying an email. See:  
> https://github.com/horde/imp/commit/5186ad002b0809960fd6096a2ca85ab8d2aab888

There are similar commits in other files. I took a shot and applied

https://github.com/horde/Text_Filter/commit/8d0de407dbb95626bc54eaba078191847be9c574

This commit (in my installation from PEAR packages) fixed the display  
of text-only messages. This commit (and similar ones) seems to be  
mandatory to make Horde run under PHP 7.3, so I'd vote for backporting  
these.

Thanks for showing me the right direction.

>
> Also, please make sure you are up to date with git on *all*  
> packages. I know there were a few similar fixes not *too* long ago  
> in some other packages, like Text_Filter.