Following T121597#4652873 and T121597#4681823 I talked with @Joe and we agreed that we need to take a close look at our INI settings and make sure they are as identical as possible, with any differences either fixed or justified+documented.
With the very limited use of PHP 7 so far, we've already encountered one major difference which is that our current PHP 7 settings partially disable error_reporting, which is a problem. See also T187147 about that.
Todo from T211488#5102911:
- Differences in APC settings.
- Differences in Filesytem settings.
- Differences in Serialisation settings.
- Differences in Error handling.
- Differences in File Uploads settings.
- Differences in Session settings.
- Differences in Mail settings.
- Intl settings.
- OPCache settings.
- Redis settings.
- Mysql settings.
- Memcached settings.
- Decide on PCRE JIT.
- Decide on enable_dl. See T220681
- Fix include_path.
- Fix doc_root .
- Hard limit
- Stat cache