os-aix/3913: Syntax Error in httpd.conf: Expected but saw

[Teo Chee Keong <ck...@mas.gov.sg>]

>Number:         3913
>Category:       os-aix
>Synopsis:       Syntax Error in httpd.conf: Expected </Directory> but saw </Directory>
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    apache
>State:          open
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Wed Feb 17 18:50:01 PST 1999
>Last-Modified:
>Originator:     ckteo@mas.gov.sg
>Organization:
apache
>Release:        1.3.*
>Environment:
AIX 4.3.2 OS, C for AIX Compiler 4.4
>Description:
After compiling and installing 1.3.*, httpd fails to start with the following error:
"Syntax error on line 285 of /apache/conf/httpd.conf:
Expected </Directory> but saw </Directory>"

This is a known problem due to a bug in the C for AIX compiler. Check PR 2312, 2534, 2664, 2853, and 3042 for more details. However, it was mentioned in PR 2312 that the PTF or fix to resolve it would be out only in Apr 99 for C for AIX 4.4 by IBM.

What I can suggest here is a solution for those who cannot wait till Apr 99 or are using an older version of C for AIX.
>How-To-Repeat:

>Fix:
Yes, but you need to do a few things:

First, edit the http_core.c file. Made the following changes to the end_nested_section() function as follow:
===========================================================
static const char *end_nested_section(cmd_parms *cmd, void *dummy)
{
    int answercode=123;

    if (cmd->end_token == NULL) {
        return ap_pstrcat(cmd->pool, cmd->cmd->name,
                          " without matching <", cmd->cmd->name + 2,
                          " section", NULL);
    }
    /*
     * This '!=' may look weird on a string comparison, but it's correct --
     * it's been set up so that checking for two pointers to the same datum
     * is valid here.  And faster.
     */

    /* Modification by Teo Chee Keong to work with AIX 4.3.2 and
       C for AIX compiler 4.4
       Date Modified: 12/02/99
     */

    /* if (cmd->cmd->name != cmd->end_token) {  <-- replaced by line below */

    if(strcmp(cmd->cmd->name,cmd->end_token)) {
        return ap_pstrcat(cmd->pool, "Expected ", cmd->end_token, " but saw ",
                          cmd->cmd->name, NULL);
    }
    return cmd->end_token;
}
=============================================================
The above amendment uses the traditional string comparsion routine (which is slower)  instead of the so-called "weird" "!=" operator. Remember to include strings.h in the beginning of the file. This would only made Apache server slower when reading configuration files and should not affect run-time performance.

Next, you may also need to modify function ap_md5() in util_md5.c as the C for AIX compiler may be quite strict on implicit data type conversion. The amendment below does this:
=================================================
API_EXPORT(char *) ap_md5(pool *p, const unsigned char *string)
{
    /* Modification by Teo Chee Keong for AIX 4.3.2 and C for AIX Compiler 4.4
       Date modified: 12/02/99
       Modified due to stricter checking by C for AIX compiler on data types
    */
    const char *ckteo;            /* declare tmp variable        */
    ckteo=(const char *)string;   /* forced data type conversion */
    return ap_md5_binary(p, string, strlen(ckteo));
}
===========================================

Lastly, recompile again ,ie, run make again. I have tried this method on my machine and it works.
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