Avoid empty first part for global namespace in NameResolver::resolveC…

[VolCh]

…lassName

During investigate goaop/parser-reflection#80 and goaop/parser-reflection#83 I found that root of issue is in Name::$parts[0] === '' in global namespace which append by NameResolver::resolveClassName during resolve class names using in global namespace like fetch class const.

[nikic]

Do you have a reproduce script for this? This looks like a usage mistake to me, as the parser shouldn't ever generate a namespace for which toString() is ''.

[VolCh]

As far I understand it generated by new Namespace_(new FullyQualified(''), ...) at https://github.com/goaop/parser-reflection/blob/master/src/NodeVisitor/RootNamespaceNormalizer.php#L47
during parsing file without any namespace, i. e. global namespaces

P.S. What is expected behavior for (new Namespace_(new FullyQualified('')))->toString() ?

[nikic]

That's the problem then. The global namespace is represented using new Namespace(null, ...), not new Namespace_(new FullyQualified(''), ...). Generally names with empty components are always invalid. I guess it would be good to add an explicit check + exception in this case.

[nikic]

I've added an exception on empty names in master: b507fa4 Not changing this in 3.x for BC reasons. It looks like goaop/parser-reflection already has an open PR to fix this issue: goaop/parser-reflection#68