OpenEuphoria

1. Win32Lib bug in registerControl()

• Posted by ghaberek (admin) Mar 13, 2012
• 1327 views

So I've been playing around with custom controls, and I'm pretty sure I found bug. The documentation for registerControl() states:

However, in the code (around line 26296), there is this:

26296    lClass = call_func(pRID[kCRID_Control], {"classType", -1}) 
26297    classAlias[lControl] = lClass 
26298    classType[lControl] = classType[lClass] 

If the "Control" routine returns the default -1 as stated in the docs, the application crashes since it is trying to use lClass as an index into classType.

C:\EUPHORIA\Win32Lib\Include\win32lib.ew:26298 in function registerControl() 
subscript value -1 is out of bounds, reading from a sequence of length 62 

And I'm honestly not too sure how to go about fixing it.

-Greg

3. Re: Win32Lib bug in registerControl()

• Posted by ghaberek (admin) Mar 13, 2012
• 1290 views

Poking around, I thought I could just add an if statement like this:

if lClass != -1 then 
    classType[lControl] = classType[lClass] 
end if 

...then things broke even worse later on.

C:\EUPHORIA\Win32Lib\Include\win32lib.ew:26314 in function registerControl() 
subscript value -1 is out of bounds, reading from a sequence of length 62 

Which is this line:

26314    classKbdInput[lControl] = call_func(pRID[kCRID_Control], {"classKbdInput", classKbdInput[lClass]}) 

-Greg

5. Re: Win32Lib bug in registerControl()

• Posted by DerekParnell (admin) Mar 14, 2012
• 1265 views

26296    lClass = call_func(pRID[kCRID_Control], {"classType", -1}) 
26297    classAlias[lControl] = lClass 
26298    classType[lControl] = classType[lClass] 

C:\EUPHORIA\Win32Lib\Include\win32lib.ew:26298 in function registerControl() 
subscript value -1 is out of bounds, reading from a sequence of length 62 

The fix is simple. The documentation is wrong. It should read ...

In other words, your new control must return a valid class type. If your new control's registration routine fails to do that, your application will crash.