Detect old database setup

[leofeyer]

The changes from 51134b5 need to be re-added (and adjusted) to prevent the issue from #282. If the MySQL version is lower than 5.7.7, there are only two options to run Contao:

• Enable large prefixes
• Use MyISAM and utf8

[fritzmg]

Agreed. Why was it removed in the first place?

[leofeyer]

Silly me…

[leofeyer]

Re-added in e8d6349. I have also extended the unit tests to check different database versions.

[fritzmg]

Since you re-added the variable index length depending on the database configuration, is the message in the install tool still strictly necessary?

[leofeyer]

What exactly do you mean?

[fritzmg]

May be I am misunderstanding this, but the main problem of #282 was the too long index length, that Contao wanted to create. In e8d6349 you have made some changes to getDefaultIndexLength - I am assuming this would actually fix it, without setting

innodb_large_prefix = 1
innodb_file_format = Barracuda
innodb_file_per_table = 1

or

doctrine:
    dbal:
        connections:
            default:
                default_table_options:
                    charset: utf8
                    collate: utf8_unicode_ci
                    engine: MyISAM

?

[leofeyer]

I am assuming this would actually fix it, without setting

Nope, it does not.

[ausi]

@fritzmg getDefaultIndexLength() can only be used for regular indexes. The issue stays for UNIQUE indexes because they cannot have a length limit.

[fritzmg]

I see, thank you for the explanation :)