FIX: The MultiByteToWideChar function returns an unexpected value on a Windows CE .NET 4.2-based device

Consider the following scenario. On a Microsoft Windows CE .NET 4.2-based device, you call the MultiByteToWideChar function in your code. You set the value of the fourth parameter of the MultiByteToWideChar function to -1. In this scenario, the MultiByteToWideChar function returns an unexpected value.

For example, you run the following code on the Windows CE .NET 4.2-based device. You expect the MultiByteToWideChar function to return a value of 4 for the len variable. However, the MultiByteToWideChar function returns a value of 3 for the len variable.

Software update information

A supported software update is now available from Microsoft as Windows CE .NET 4.2 Platform Builder Monthly Update (September 2007). You can confirm this by scrolling to the "File information" section of this article. The package file name contains the product version, date, Knowledge Base article number, and processor type. The package file name format is:For example: Wincepb50-060503-kb917590-armv4i.msi is the ARMV4i Windows CE 5.0 Platform Builder fix that is documented in KB article 917590 and that is contained in the May 2006 monthly update. To resolve this problem immediately, click the following article number for information about obtaining Windows CE Platform Builder and core operating system software updates:

Prerequisites

This update is supported only if all previously issued updates for this product are also installed.

Restart requirement

After you apply this update, you must perform a clean build of the whole platform. To clean the platform, click Clean on the Build menu. To build the platform, click Build Platform on the Build menu. You do not have to restart the computer after you apply this update.

Update replacement information

This update does not replace any other updates.

File information

The English version of this package has the file attributes (or later file attributes) that are listed in the following table. The English version of this update has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

For more information about the MultiByteToWideChar function, visit the following Microsoft Developer Network (MSDN) Web site: For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base: