# ReactOS Newsletter 50: PSEH2 Exception Issues, MSVCRT Testing, and Win32k Initialization

DevFeed: [ReactOS Newsletter 50: PSEH2 Exception Issues, MSVCRT Testing, and Win32k Initialization](<https://devfeed.tech/articles/newsletter-50-32916.md>)

Original publisher: [Read original article](<https://reactos.org/blogs/newsletter-50/>)

Published: 2008-12-20T00:00:00Z

Content type: article

Language: en

Sources: [Front Page on ReactOS Website](<https://devfeed.tech/sources/front-page-on-reactos-website.md>)

Topics: [ReactOS](<https://devfeed.tech/topics/reactos.md>), [exceptions](<https://devfeed.tech/topics/exceptions.md>), [unit tests](<https://devfeed.tech/topics/unit-tests.md>), [C++](<https://devfeed.tech/topics/c-plus-plus.md>), [WINE](<https://devfeed.tech/topics/wine.md>)

Tags: [c-plus-plus](<https://devfeed.tech/tags/c-plus-plus.md>), [crash](<https://devfeed.tech/tags/crash.md>), [exceptions](<https://devfeed.tech/tags/exceptions.md>), [free](<https://devfeed.tech/tags/free.md>), [open-source](<https://devfeed.tech/tags/open-source.md>), [os](<https://devfeed.tech/tags/os.md>), [react](<https://devfeed.tech/tags/react.md>), [reactos](<https://devfeed.tech/tags/reactos.md>), [tests](<https://devfeed.tech/tags/tests.md>), [unit-tests](<https://devfeed.tech/tags/unit-tests.md>), [win32](<https://devfeed.tech/tags/win32.md>), [winapi](<https://devfeed.tech/tags/winapi.md>), [wine](<https://devfeed.tech/tags/wine.md>)

## AI overview

This ReactOS newsletter discusses data corruption and crashes associated with the relatively untested PSEH2 implementation, ongoing fixes and SEH test development, login input-component problems, MSVCRT compatibility work, and unit testing against Wine.

## Source excerpt

The Perils of PSEH2 While KJK did get PSEH2 out in record time, this meant that it was relatively untested when he committed it and developers began using it. Currently PSEH seems to be corrupting data when exceptions get thrown, which then cascades down and causes functions to assert and crash, something that it was supposed to prevent. Michael Martin's theory about what is happening is that PSEH is clobbering local variables that are being held in registers, though KJK attributes it to an issue of not using setjmp.