[5.3] Fix #16593 and fix bug introduced in #16607

[manan-jadhav]

The regex now handles array syntax, with/without 'or' nicely.

I've added tests to verify that this fixes #16593 .

[taylorotwell]

Can you explain this regex in plain English?

[vlakoff]

Are you sure the two greedy .+ you have added aren't problematic?

[manan-jadhav]

@vlakoff There are unit tests which cover all possibilities, and they pass, so I dont think they're going to cause any problems now. If there are more cases in your head, let me know.

[manan-jadhav]

This is the regex : ^(\$.+(?:\[[\'"].+[\'"]\])|[^\[\]\'"]*)(?:\s+or\s+)(.+)$

Breaking it into three parts :

1. (\$.+(?:\[[\'"].+[\'"]\])|[^\[\]\'"]*) : This gets captured in group 1 $1.
   Match things that start with a $ then followed by one or more characters (.+) then followed by either of the following

   • (?:\[[\'"].+[\'"]\]) : String that opens with [' or [", then contains characters (using greedy here makes sure the regex doesnt return too early), and then '] or "]. This matches the array access statements.
   • [^\[\]\'"]* : String that is empty, OR, does not contain any of [, ", '. This matches anything except the array access statements.

2. (?:\s+or\s+) : Matches or, that is, or with whitespace characters around it.

3. (.+) : This gets captured in group 2 $2. Matches any characters after or.

[taylorotwell]

Going to hold off on this for now on 5.3 as it's fairly edge case and I don't want to break things again on a minor release.

[vlakoff]

Another case to think of, and test, would be dynamic variable names:

$foo = new \StdClass;
$foo->bar = 'content';
$dynName = 'bar';

// note the brackets
{{ $foo->{$dynName} }}