Issues with using `System.Win32.Registry` about win32 HOT 2 CLOSED

Hi,

Thanks for opening an issue. So

1. regQueryValue type seems correct to me, at least signature wise, it's return value on msdn (lpValue) is LPTSTR. However you're in that the behavior is wrong.

2. Yes this is suspicious and I don't know why it was done. These two should be functionally the same if the subkey value is combined into the HKEY. But it doesn't seem to do that.

3. No reason it can't be added, no one has ever needed it before, that's the only reason it's not there. I'd be happy to accept a pull request to add it. That would be the quickest, otherwise I'll try to find time to add it soon.

4. I wouldn't mind such helper functions, since we already have some for error handling. I don't however want to restrict it to just these registry functions. so I would prefer something like getStorableValue :: forall a b. Storable b => String -> (a -> b) -> a -> IO b where the first String is the name of the function to put in the error message who's result couldn't be decoded. This would match the other helpers that exist and wouldn't be so specific.

I don't mind breaking changes, but I would mind a breaking change with the same signature, as this is a silent breaking change. Luckily there's some wiggle room here as the documentation for regQueryValue indicates it should be able to take a NULL and empty string. So I don't mind correcting the behavior of the function if the signature also changes to take a Maybe String so a compile error is issued to people using these functions who may not have read the changelog or are ignoring version bounds.

Since you are already working in this area, a pull request would be much appreciated!, otherwise I will fix these as soon as I can.

from win32.

Ah. I made more than one mistake in reading the docs, my apologies. The comment I criticised is correct, as RegQueryValue "Retrieves the data associated with the default or unnamed value of a specified registry key." That also explains my confusion over the return type as it looks like the default/unnamed value of a key is always of type REG_SZ.

I do intend to make a PR but might take me a while to get my head around various bits!

from win32.