Topic: mod_fcgid on Windows XP and FastCGI apps build by VC++ 2005

[vitalus]

This is important! I lost several days to find out what was wrong.. (@ see http://www.apachelounge.com/viewtopic.php?t=3051).

If you build FastCGI applications using Visual C++ 2005, 2008,.. (by those versions that use manifest for dependency management on C Runtime library known as msvcrXX.dll) remember to use the following declarations in httpd.conf:
...
DefaultInitEnv SystemRoot "C:\WINDOWS"
...

What is special here comparing to original docs (http://fastcgi.coremail.cn/doc.htm) - is a "\" but not "/"!!

The path "C:/WINDOWS" leads to R6034 exception (C Run-Time Error R6034).

It is XP only problem, on Vista, Windows Server 2003 the slash direction is not important.

Why is it so? It is because of _check_manifest() function fails during CRT initialization. See there:

static BOOL __cdecl _check_manifest(HMODULE hDllHandle)

{

/* We check that the dll is loaded through a manifest.
*
* We check several conditions and exceptions:
*
* (1) if (pre-fusion OS)
* return TRUE; [no need to check]
*
* (2) if dll is being loaded by instrumented-mscoree.dll.
* return TRUE;
*
* (3) if (dll is loaded from system32)
* return FALSE;
*
* (4) if (!(loaded through a manifest))
* return FALSE;
*
* (5) if (loaded from %SystemRoot%\WinSxS)
* return TRUE; [loaded from the WinSxS cache]
*
* (6) if (manifest is in the same folder as the dll)
* return TRUE;
*
* (7) return FALSE; [loaded with another manifest]
*
* In general, when we encounter an error condition or something
* which blocks us from checking if the dll is loaded through a
* manifest, we do not return an error, but we let the dll to be
* loaded. Notice that this is not a security feature: it's an helper
* which will try (as much as possible) to discourage the practice
* of not using a manifest to load the crt dll.
*/

The 5th checking fails on XP with a path "C:/WINDOWS\WinSxS" .... seems it is a simple copmarison without pre-formatting of the path on XP, improved on later OS versions.