QHelpEngine: ignores a search path as defined in a QDir::searchPath

QHelpEngine accepts a QString in its constructor containing a collection file. The superclass QHelpEngineCore has the method registerDocumentation( QString& ) which can accept a file name (.qch) containing documentation.

When using QDir::setSearchPaths("help", <search paths>) to register a prefix "help" with one or more search paths and the prefix is subsequently used in a call to registerDocumentation on a QHelpEngine, the call returns false indicating that it hasn't been successful.

This reproduces under Windows and X11 with Qt versions 4.5.0 and 4.4.3