Runtime Changes for Migration from .NET Framework 4.5 to 4.5.2

[ad_1]




Introduction

Runtime changes affect all apps that are running under a .NET Framework it was not compiled against and that use a particular feature.

In the topics that describe runtime changes, we have classified individual items by their expected impact, as follows:

Major
This is a significant change that affects a large number of apps or that requires substantial modification of code.

Minor
This is a change that affects a small number of apps or that requires minor modification of code.

Edge case
This is a change that affects apps under very specific scenarios that are not common.

Transparent
This is a change that has no noticeable effect on the app’s developer or user. The app should not require modification because of this change.

If you are migrating from the .NET Framework 4.5 to 4.5.2, review the following topics for application compatibility issues that may affect your app:

ADO.NET

ADO.NET now attempts to automatically reconnect broken SQL connections

ASP.NET

ASP.NET MVC now escapes spaces in strings passed in via route parameters

Details In order to conform to RFC 2396, spaces in route paths are now escaped when populating action parameters from a route. So, whereas /controller/action/some data would previously match the route /controller/action/data and provide some data as the data parameter, it will now provide some%20data instead.
Suggestion Code should be updated to unescape string parameters from a route. If the original URI is needed, it can be accessed with the RequestUri.OriginalString API.
Scope Minor
Version ۴٫۵٫۲
Type Runtime
Affected APIs

No longer able to set EnableViewStateMac to false

Details ASP.NET no longer allows developers to specify <pages enableViewStateMac="false"/> or &lt;@Page EnableViewStateMac="false" %>. The view state message authentication code (MAC) is now enforced for all requests with embedded view state. Only apps that explicitly set the EnableViewStateMac property to false are affected.
Suggestion EnableViewStateMac must be assumed to be true, and any resulting MAC errors must be resolved (as explained in this guidance, which contains multiple resolutions depending on the specifics of what is causing MAC errors).
Scope Major
Version ۴٫۵٫۲
Type Runtime

Profiling ASP.Net MVC4 apps can lead to Fatal Execution Engine Error

Details Profilers using NGEN /Profile assemblies may crash profiled ASP.NET MVC4 applications on startup with a ‘Fatal Execution Engine Exception’
Suggestion This issue is fixed in the .NET Framework 4.5.2. Alternatively, the profiler may avoid this issue by specifying COR_PRF_DISABLE_ALL_NGEN_IMAGES in its event mask.
Scope Edge
Version ۴٫۵
Type Runtime

Core

A ConcurrentDictionary serialized in .NET Framework 4.5 with NetDataContractSerializer cannot be deserialized by .NET Framework 4.5.1 or 4.5.2

Details Due to internal changes to the type, ConcurrentDictionary<TKey,TValue> objects that are serialized with the .NET Framework 4.5 using the NetDataContractSerializer cannot be deserialized in the .NET Framework 4.5.1 or in the .NET Framework 4.5.2.Note that moving in the other direction (serializing with the .NET Framework 4.5.x and deserializing with the .NET Framework 4.5) works. Similarly, all 4.x cross-version serialization works with the .NET Framework 4.6.Serializing and deserializing with a single version of the .NET Framework is not affected.
Suggestion If it is necessary to serialize and deserialize a ConcurrentDictionary<TKey,TValue> between the .NET Framework 4.5 and .NET Framework 4.5.1/4.5.2, an alternate serializer like the DataContractSerializer or BinaryFormatter serializer should be used instead of the NetDataContractSerializer.Alternatively, because this issue is addressed in the .NET Framework 4.6, it may be solved by upgrading to that version of the .NET Framework.
Scope Minor
Version ۴٫۵٫۱
Type Runtime

ConcurrentQueue<T>.TryPeek can return an erroneous null via its out parameter

Details In some multi-threaded scenarios, TryPeek(T) can return true, but populate the out parameter with a null value (instead of the correct, peeked value).
Suggestion This issue is fixed in the .NET Framework 4.5.1. Upgrading to that Framework will solve the issue.
Scope Major
Version ۴٫۵
Type Runtime
Affected APIs

COR_PRF_GC_ROOT_HANDLEs are not being enumerated by profilers

Details In the .NET Framework v4.5.1, the profiling API RootReferences2() is incorrectly never returning COR_PRF_GC_ROOT_HANDLE (they are returned as COR_PRF_GC_ROOT_OTHER instead). This issue is fixed beginning in the .NET Framework 4.6.
Suggestion This issue has been fixed in the .NET Framework 4.6 and may be addressed by upgrading to that version of the .NET Framework.
Scope Minor
Version ۴٫۵٫۱
Type Runtime

Deserialization of objects across appdomains can fail

Details In some cases, when an app uses two or more app domains with different application bases, trying to deserialize objects in the logical call context across app domains throws an exception.
Suggestion See Mitigation: Deserialization of Objects Across App Domains
Scope Edge
Version ۴٫۵٫۱
Type Runtime

EventListener truncates strings with embedded nulls

EventSource.WriteEvent impls must pass WriteEvent the same parameters that it received (plus ID)

Details The runtime now enforces the contract that specifies the following: A class derived from EventSource that defines an ETW event method must call the base class EventSource.WriteEvent method with the event ID followed by the same arguments that the ETW event method was passed.
Suggestion An IndexOutOfRangeException exception is thrown if an EventListener reads EventSource data in process for an event source that violates this contract.
Scope Minor
Version ۴٫۵٫۱
Type Runtime

Marshal.SizeOf and Marshal.PtrToStructure overloads break dynamic code

Details Beginning in the .NET Framework 4.5.1, dynamically binding to the methods SizeOf<T>(), SizeOf<T>(T), PtrToStructure(IntPtr, Object), PtrToStructure(IntPtr, Type), PtrToStructure<T>(IntPtr), or PtrToStructure<T>(IntPtr, T), (via Windows PowerShell, IronPython, or the C# dynamic keyword, for example) can result in MethodInvocationExceptions because new overloads of these methods have been added that may be ambiguous to the scripting engines.
Suggestion Update scripts to clearly indicate which overload should be used. This can typically done by explicitly casting the methods’ type parameters as Type. See this link for more detail and examples of how to workaround the issue.
Scope Minor
Version ۴٫۵٫۱
Type Runtime

Some .NET APIs cause first chance (handled) EntryPointNotFoundExceptions

WinRT stream adapters no long call FlushAsync automatically on close

Details In Windows Store apps, Windows Runtime stream adapters no longer call the FlushAsync method from the Dispose method.
Suggestion This change should be transparent. Developers can restore the previous behavior by writing code like this:

using (var stream = GetWindowsRuntimeStream() as Stream)

// do something
await stream.FlushAsync();

Scope Transparent
Version ۴٫۵٫۱
Type Runtime

Data

ADO.NET now attempts to automatically reconnect broken SQL connections

SqlConnection.Open fails on Windows 7 with non-IFS Winsock BSP or LSP present

Details Open() and OpenAsync(CancellationToken) fail in the .NET Framework 4.5 if running on a Windows 7 machine with a non-IFS Winsock BSP or LSP are present on the computer.To determine whether a non-IFS BSP or LSP is installed, use the netsh WinSock Show Catalog command, and examine every Winsock Catalog Provider Entry item that is returned. If the Service Flags value has the 0x20000 bit set, the provider uses IFS handles and will work correctly. If the 0x20000 bit is clear (not set), it is a non-IFS BSP or LSP.
Suggestion This bug has been fixed in the .NET Framework 4.5.2, so it can be avoided by upgrading the .NET Framework. Alternatively, it can be avoided by removing any installed non-IFS Winsock LSPs.
Scope Minor
Version ۴٫۵
Type Runtime
Affected APIs

Entity Framework

EF no longer throws for QueryViews with specific characteristics

Details Entity Framework no longer throws a StackOverflowException exception when an app executes a query that involves a QueryView with a 0..1 navigation property that attempts to include the related entities as part of the query. For example, by calling .Include(e => e.RelatedNavProp).
Suggestion This change only affects code that uses QueryViews with 1-0..1 relationships when running queries that call .Include. It improves reliability and should be transparent to almost all apps. However, if it causes unexpected behavior, you can disable it by adding the following entry to the <appSettings> section of the app’s configuration file:

<add key="EntityFramework_SimplifyUserSpecifiedViews" value="false" />
Scope Edge
Version ۴٫۵٫۲
Type Runtime

Opt-in break to revert from different 4.5 SQL generation to simpler 4.0 SQL generation

Details Queries that produce JOIN statements and contain a call to a limiting operation without first using OrderBy now produce simpler SQL. After upgrading to .NET Framework 4.5, these queries produced more complicated SQL than previous versions.
Suggestion This feature is disabled by default. If Entity Framework generates extra JOIN statements that cause performance degradation, you can enable this feature by adding the following entry to the <appSettings> section of the application configuration (app.config) file:

<add key="EntityFramework_SimplifyLimitOperations" value="true" />
Scope Transparent
Version ۴٫۵٫۲
Type Runtime

Serialization

NetDataContractSerializer fails to deserialize a ConcurrentDictionary serialized with a different .NET version

Windows Communication Foundation (WCF)

MinFreeMemoryPercentageToActiveService is now respected

Details This setting establishes the minimum memory that must be available on the server before a WCF service can be activated. It is designed to prevent OutOfMemoryException exceptions. In the .NET Framework 4.5, this setting had no effect. In the .NET Framework 4.5.1, the setting is observed.
Suggestion An exception occurs if the free memory available on the web server is less than the percentage defined by the configuration setting. Some WCF services that successfully started and ran in a constrained memory environment may now fail.
Scope Minor
Version ۴٫۵٫۱
Type Runtime

Windows Presentation Foundation (WPF)

Calling DataGrid.CommitEdit from a CellEditEnding handler drops focus

Intermittently unable to scroll to bottom item in ItemsControls (like ListBox and DataGrid) when using custom DataTemplates

Details In some instances, a bug in the .NET Framework 4.5 is causing ItemsControls (like ListBox, ComboBox, DataGrid, etc.) to not scroll to their bottom item when using custom DataTemplates. If the scrolling is attempted a second time (after scrolling back up), it will work then.
Suggestion This issue has been fixed in the .NET Framework 4.5.2 and may be addressed by upgrading to that version (or a later version) of the .NET Framework. Alternatively, users can still drag scroll bars to the final items in these collections, but may need to try twice to do so successfully.
Scope Minor
Version ۴٫۵
Type Runtime

Scrolling a WPF TreeView or grouped ListBox in a VirtualizingStackPanel can cause a hang

Details In the .NET Framework v4.5, scrolling a WPF TreeView in a virtualized stack panel can cause hangs if there are margins in the viewport (between the items in the TreeView, for example, or on an ItemsPresenter element). Additionally, in some cases, different sized items in the view can cause instability even if there are no margins.
Suggestion This bug can be avoided by upgrading to .NET Framework 4.5.1. Alternatively, margins can be removed from view collections (like TreeViews) within virtualized stack panels if all contained items are the same size.
Scope Major
Version ۴٫۵
Type Runtime
Affected APIs

WPF spawns a wisptis.exe process which can freeze the mouse

Details An issue was introduced in 4.5.2 that causes wisptis.exe to be spawned that can freeze mouse input.
Suggestion A fix for this issue is available in a servicing release of the .NET Framework 4.5.2 (hotfix rollup 3026376), or by upgrading to the .NET Framework 4.6
Scope Major
Version ۴٫۵٫۲
Type Runtime

[ad_2]

source_link
https://www.asp.net