Bug 36004 - Linq Method Groups are broken
Summary: Linq Method Groups are broken
Alias: None
Product: Android
Classification: Xamarin
Component: Mono runtime / AOT Compiler ()
Version: 6.0.99
Hardware: PC Windows
: Normal normal
Target Milestone: ---
Assignee: Jonathan Pryor
Depends on:
Reported: 2015-11-18 10:12 UTC by Caan Mee
Modified: 2017-06-28 11:52 UTC (History)
3 users (show)

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

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Description Caan Mee 2015-11-18 10:12:07 UTC
After upgrading to Xamarin 4 my app kept crashing, with the following exception:

I/MonoDroid( 8039): System.ArrayTypeMismatchException: Attempted to access an element as a type incompatible with the array.
I/MonoDroid( 8039):   at (wrapper stelemref) System.Object:virt_stelemref_class (intptr,object)
I/MonoDroid( 8039):   at System.Linq.Lookup`2+Grouping[TKey,TElement].Add (TElement element) <0x98726e30 + 0x0005f> in <filename unknown>:0
I/MonoDroid( 8039):   at System.Linq.Lookup`2[TKey,TElement].Create[TSource] (IEnumerable`1 source, System.Func`2 keySelector, System.Func`2 elementSelector, IEqualityComparer`1 comparer) <0x987265f8 + 0x000cf> in <filename unknown>:0
I/MonoDroid( 8039):   at System.Linq.GroupedEnumerable`3[TSource,TKey,TElement].GetEnumerator () <0x98726570 + 0x0002f> in <filename unknown>:0
I/MonoDroid( 8039):   at System.Linq.Buffer`1[TElement]..ctor (IEnumerable`1 source) <0x9c60c740 + 0x000cc> in <filename unknown>:0
I/MonoDroid( 8039):   at System.Linq.OrderedEnumerable`1+<GetEnumerator>c__Iterator0[TElement].MoveNext () <0x9b3b8990 + 0x0007b> in <filename unknown>:0
I/MonoDroid( 8039):   at System.Linq.Enumerable+WhereSelectEnumerableIterator`2[TSource,TResult].MoveNext () <0x9c407ee0 + 0x00135> in <filename unknown>:0

The line which caused the exception:

var models = dtos.Select(AutoMapper.Map<MyModel>).ToList();

when I convert the code to:
var models = dtos.Select(m => AutoMapper.Map<MyModel>(m)).ToList();

it seems to work flaweless.
Comment 1 Jonathan Pryor 2015-11-18 12:07:03 UTC
Please attach a test case so that we can more easily reproduce this.
Comment 2 Adam Hartley [MSFT] 2017-06-28 11:52:18 UTC
Because we have not received a reply to our request for more information we are closing this issue. If you are still encountering this issue, please reopen the ticket with the requested information. Thanks!