Serious Bug System.Collecti ons Sort

[william.hooper]

There is a longer article about this subject here:
http://www.codeproject.com/useritems/SortedList_Bug.asp
See the main article and the reply thread started by Robert Rohde.

Alternatively look at this code:

ArrayList a=new ArrayList();

string s1 = "-0.67:-0.33:0.33";
string s2 = "0.67:-0.33:0.33";
string s3 = "-0.67:0.33:-0.33";

a.Add(s1);
a.Add(s2);
a.Add(s3);

a.Sort();
for (int i=0; i<3; i++) Console.WriteLi ne( a[i] );

Console.WriteLi ne();

a.Clear();
a.Add(s1);
a.Add(s3);
a.Add(s2);

a.Sort();
for (int i=0; i<3; i++) Console.WriteLi ne( a[i] );

This code produces the following six lines of output:

-0.67:0.33:-0.33
0.67:-0.33:0.33
-0.67:-0.33:0.33

-0.67:-0.33:0.33
-0.67:0.33:-0.33
0.67:-0.33:0.33

Note that the .Sort produces different outputs depending on the order
the strings are added.

It looks like the Sort algorithm is ignoring the "-" mark.

This is a very serious Bug impacting the System.Collecti ons Array,
SortedList etc.

[w.hooper]

>Chris Dunaway wrote:

>
And FWIW, I didn't see this issue officially reported on the feedback
site. You may wish to post it there.

Chris, what is the feedback site? I would liek to post it there. It's
really annoying and you never know, they might take an interest.

[w.hooper]

Thanks very much that's great. I will keep an eye on it.

[Marc Gravell]

See my previous post; since you didn't seem familiar with "connect" I posted
it as a bug. Feel free to go in and click "validate". .. and vote!
http://connect.microsoft.com/VisualS...dbackID=236900

And note: I wasn't trying to steal your thunder... just to get it logged
with the least fuss...

Marc

[Marc Gravell]

Still no MS viewpoint?

For ref, I think this is actually quite important, as it could (as
illustrated on the now-deleted CodeProject link) cause a whole range of
sort-critical operations to fail... SortedList etc, or any custom
collections that assume that .Sort() might actually work, and then
trust the results.

Any thoughts?

Marc

[william.hooper]

Yes absolutely, it cost me lots of time in the SortedList failing. I
think it's to do with the hyphen algorithm which is designed to sort
words with hyphens in a smart way. Obviously with two hyphens in the
word it fails. Anyone who puts two hyphens in strings is taking a huge
risk - yet using hyphens in strings is common enough. A really
dangerous bug I would say, but I guess Microsoft haven't seen that
yet. You could mention on the article that it causes problems with
SortedList and you think it's a very serious problem. I think we have
discovered a real corker and it deserves to be given a lot of attention.