[Kde-bindings] weird behaviour of some classes' #text method in korundum

[Stefano Crocco]

Hello to everyone,
I just found out what I consider a bug. There are some classes with a #text 
method which behaves strangely. Take for example the following code

require 'Qt4'
app = Qt::Application.new []
w = Qt::Label.new; p w.text # => nil
w.text = ''; p w.text # => nil
w.text = 'xyz'; p w.text # => "xyz"
w.text = ''; p w.text # => ""

It seems that Qt::Label#text returns nil until I set the text to a non-empty 
string; after that #text correctly returns a string even after I set the text 
back to '' (nothing changes if I pass an empty string as first argument to the 
constructor).

Other classes which behave this way are Qt::PushButton, Qt::CheckBox and 
KTextEditor::Document (there may be others, too. I didn't do an exhaustive 
search). Regading KTextEditor::Document, it's not only its #text method which 
behaves this way, but also #line. This means that, given the following text:
line0

line2

line4

the following snippet of code produces what I consider a very surprising 
result:

0.upto(4){|i| p doc.line(i)}

=> "line0"
=> nil
=> "line2"
=> nil
=> "line4"

The output I'd expect, of course, is:
"line0"
""
"line2"
""
"line4"

I could understand if #line returned nil when its argument is greater than the 
number of lines in the document, but I think it's wrong returning nil for an 
empty line.

Is the behaviour I described expected, or is it a bug? If it's not a bug, 
could anyone tell me which are the reasons behind it?

Thanks in advance

Stefano