os-windows/4887: bad comparison in mod_isapi.c causing problems with GetExtensionVersion()

[Sergey Verlan <sv...@hotmail.com>]

>Number:         4887
>Category:       os-windows
>Synopsis:       bad comparison in mod_isapi.c causing problems with GetExtensionVersion()
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    apache
>State:          open
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Sun Aug 22 06:40:00 PDT 1999
>Last-Modified:
>Originator:     sverlan@hotmail.com
>Organization:
apache
>Release:        1.3.9
>Environment:
Binary distribution of Apache 1.3.9 on Windows 98 OSR2
>Description:
In mod_isapi.c on line 175 there is a bad comparision:
     if ((*isapi_version)(pVer) != TRUE) {
The problem is that in BOOL type any nonzero value must be treated as TRUE.
In Microsoft Visual C the TRUE constant is binded to 1 so you can not use
this comparison. This problem specialy arises when you try to use a ISAPI dll
made by Borland Delphi, where TRUE is binded to -1.
In this case you simply get the following error message:
 No such file or directory: ISAPI GetExtensionVersion() failed:

To solve the problem you must make a comparison with FALSE which is zero 
in all cases or like I've done below.

This question was in PR4333 but there was no answer to it. 
>How-To-Repeat:
You can take any Borland Delphi (may be Borland C++) ISAPI dll and see it.
Or you can modify the TRUE constant during the compilation of a Microsoft
Visual C ISAPI dll.
>Fix:
Below is the diff file for mod_isapi.c:
175c175
<     if ((*isapi_version)(pVer) != TRUE) {
---
>     if (!(*isapi_version)(pVer)) {
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