Bug 5902 - System.Xml.XPath.Extension.XPathEvaluate() return different type as .NET 4.0 does。
Summary: System.Xml.XPath.Extension.XPathEvaluate() return different type as .NET 4.0 ...
Status: RESOLVED FIXED
Alias: None
Product: Class Libraries
Classification: Mono
Component: System.XML ()
Version: 2.10.x
Hardware: PC Linux
: --- normal
Target Milestone: Untriaged
Assignee: Bugzilla
URL:
Depends on:
Blocks:
 
Reported: 2012-06-28 03:28 UTC by sumtec
Modified: 2012-06-28 13:15 UTC (History)
2 users (show)

Tags:
Is this bug a regression?: ---
Last known good build:

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Status:
RESOLVED FIXED

Description sumtec 2012-06-28 03:28:13 UTC
The following source code returns wrong type in Mono:

var doc = XDocument.Parse("<config><item name="A" /></config>"
var temp =
    (
        from item in root.XPathSelectElements("config/*") 
        let packet = new
        {
            Config = item.XPathEvaluate("."),
            Name = item.XPathEvaluate("name(.)"),
        }
        select packet
    ).First();
Console.WriteLine(temp.Config.GetType().FullName);

As bug 2383 mentioned, the MSDN said that the return type should be "a bool, a double, a string, or an IEnumerable<T>".

When running in .NET 4.0, this piece of code returns:
System.Xml.XPath.XPathEvaluator+<EvaluateIterator>d__0`1[[System.Object, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]

Which is an "IEnumerable<object>".

However, when running in Mono 2.10.8.1-1ubun, it returns:
System.Xml.XPath.AxisIterator

It is an Iterator. And it could not cast into IEnumerable<object>, or IEnumerable.

Notice: It is quite different from bug 2383, which seems return a type which could cast into IEnumerable at least. However, in my case, it couldn't. So it is not easy to walk around so that it could run with both .NET and Mono.
Comment 1 Marek Safar 2012-06-28 13:15:01 UTC
Already fixed in mono 2.11