application:handleOpenUrl: is appending the wrong extension to the file - objective-c

Question

When I attempt to export a file to my app, from within Mail, it is sending the file to export with the wrong extension.
Here's an example:
I e-mail an attachment to myself
Open the attachment in Mail
Export the file and open with my app
The url passed to application:handleOpenUrl: is wrong
The name of the file I am attempting to export is named 'NSIS.nsi' (without quotes). Mail (iOS?) renames the file to 'NSIS.4th' when it passes it back to my app via application:handleOpenUrl. One thing I did notice is that the first extension (item) within the Exported Type UTIs > Item 0 > Conforms to UTIs > Equivalent Types > public.filename-extension is '4th' (again, without quotes).
Another thing to note is that I do have the 'nsi' extension in the same public.filename-extension array.
And yet another thing to note is that this appears to happen only with the 'nsi' extension. I haven't tested all of the extensions my app supports (there's 92 of them. I got tired after about the 40th one). But this extension in particular is having issues.
By the way here is the code sample... it really is this simple. The NSURL passed contains the wrong extension. This will log the url passed -- which is the wrong one. So, I can say for certain that there is nothing in my app that is doing something with the NSURL before it gets passed to application:handleOpenUrl:.
- (BOOL)application:(UIApplication *)application handleOpenURL:(NSURL *)url
{
NSLog(#"url: %#", url);
...
}
I also don't know if this helps, but in the Mail app it does show my app's icon next to the NSIS.nsi file. And yes, the file's name displays as 'NSIS.nsi' within Mail.
Update 2
I was able to confirm that changing the first extension to '5th' (for kicks) and then imported the 'NSIS.nsi' file it indeed changed the file extension to 'NSIS.5th'. I think what's happening is I'm defining the UTIs that my app supports incorrectly. All I want to do is say, "Hey, iOS, I support all of these file extensions. Don't change the name. Just give me the file and let me do what I need to do with it." In reality I just want my app to support all types of text files (text, utf8, utf16, etc). That's the end result.
The problem is, when I tell iOS that I support plain.text, utf8 and utf16 it still won't display my app in the list of apps that can open a file unless I specifically set the extension in the public.filename-extension array. I wish there was just an all encompassing "I support all text files" configuration value in the plist.
One other thing I noticed is that the issue does affect other file extensions. For example, I have a file that I am exporting from Mail to my app called 'Ada.adb'. iOS is returning the file as 'Ada.ada' (notice the 'a' at the end instead of a 'b'). This makes sense... I don't even have 'ada' in my list of file extensions within the public.filename-extension array or anywhere in my app for that matter.
Update 3
I figured out how to support all types of public.text files.
<key>CFBundleDocumentTypes</key>
<array>
<dict>
<key>CFBundleTypeIconFiles</key>
<array>
<string>icon_buffer_ipad_small.png</string>
<string>icon_buffer_iphone_small.png</string>
</array>
<key>LSItemContentTypes</key>
<array>
<string>public.text</string>
</array>
<key>NSExportableTypes</key>
<array>
<string>public.text</string>
</array>
<key>CFBundleTypeName</key>
<string>Source File</string>
<key>LSHandlerRank</key>
<string>Default</string>
</dict>
</array>
Essentially you need to include the NSExportableTypes in addition to the LSItemContentTypes. I'll add an update when I figure out how to make other "public.text" file types such as 4th, md, and the huge list of other file types that are public.text, associated to your app. Hopefully this won't be necessary. Regardless, I'll update with my findings.
Update 4
You guys aren't going to believe this. This issue affects every app I have tested this with. Essentially, when I attempt to export the 'Ada.adb' file it exports the file as 'Ada.ada' to every application. Wow! I'm going to figure out how to file this bug with Apple. Unless, of course, this is expected behavior!
Small update: I filed the bug to Apple. Bug ID# 12802236
I do not recall this occurred in iOS 5. I believe this is a regression introduced in iOS 6.

Answer 1

If the file name doesn't change, how about change its extension manually after - (BOOL)application:(UIApplication *)application handleOpenURL:(NSURL *)url receive the url? Of course, you have to know what the right extension is.