Re: FW: [ nunit-Bugs-1923458 ] Unexpected result from AreEqual/ANE for encoded strings

Hi Charlie,

Been mia for a while.  Got behind, then got married, and just now 
getting caught up.  Figured this would be a good one to comment on 
first.  My initial thought on this is that I don't really understand 
it.  How can a string have a different encoding than another?  According 
to MSDN, each System.String is "a series of Unicode characters."  It 
could also be thought of as a series of System.Char objects, and each 
System.Char is "a Unicode character."  No where for the documentation of 
System.String do I see a way to specify the internal storage mechanism.  
My interpretation has always been that Microsoft made an effort to 
separate strings from the storage required for them, so while there 
obviously is internal storage, it is opaque.  That storage mechanism 
could change from UTF-16 today to UTF-8 tomorrow, and no application 
should care, because it is only dealing with the characters, not the 
bytes.  Is there something I am missing (likely) for how to specify a 
specific encoding for a string?  As for String.Equals() and ==, I've not 
ever gotten them to behave differently than String.Compare(), but I've 
not gotten separate strings to use separate encodings.  There is a 
culture difference, but I've never been in a situation where that makes 
a difference, particularly for equality only tests.

Given that I consider a System.String to be encoding ambivalent, I would 
think that the current behaviour, comparing individual Unicode 
characters, discarding any encoding, makes perfect sense.  Perhaps I am 
thinking about it wrong, but I think it works as it should.

Thanks,

dmp

Charlie Poole wrote:
> Hi All,
>
> I'm forwarding this bug to the list for discussion. You can comment here or
> on the bug.
>
> The gist of it is that Assert.AreEqual on strings uses string.Compare and
> can find two strings equal even if they use different encodings. This makes
> sense to me but it isn't how string.Equals or operator == work.
>
> Your thoughts?
>
> Charlei
>
> -----Original Message-----
> From: Nobody [mailto:[email protected]] On Behalf Of
> SourceForge.net
> Sent: Saturday, March 22, 2008 10:26 PM
> To: [email protected]
> Subject: [ nunit-Bugs-1923458 ] Unexpected result from AreEqual/ANE for
> encoded strings
>
> Bugs item #1923458, was opened at 2008-03-23 06:25 Message generated for
> change (Tracker Item Submitted) made by Item Submitter You can respond by
> visiting: 
> https://sourceforge.net/tracker/?func=detail&atid=110749&aid=1923458&group_i
> d=10749
>
> Please note that this message will contain a full copy of the comment
> thread, including the initial issue submission, for this request, not just
> the latest update.
> Category: framework
> Group: 2.4.5
> Status: Open
> Resolution: None
> Priority: 5
> Private: No
> Submitted By: Morten Mertner (mnmr)
> Assigned to: Nobody/Anonymous (nobody)
> Summary: Unexpected result from AreEqual/ANE for encoded strings
>
> Initial Comment:
> I would expect the following test to pass, however, it does not. 
>
> The strings do show up as different in the debugger (obviously, since
> they're encoded differently) and the built-in == operator correctly returns
> false when comparing the two variables.
>
> [Test]
> public void Simple()
> {
> 	string input = "Hello World";
> 	byte[] data = Encoding.UTF32.GetBytes( input );
> 	string garbage = Encoding.UTF8.GetString( data );
> 	Assert.AreNotEqual( input, garbage );
> }
>
>
> ----------------------------------------------------------------------
>
> You can respond by visiting: 
> https://sourceforge.net/tracker/?func=detail&atid=110749&aid=1923458&group_i
> d=10749
>
>
>
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