Merge pull request #990 from hprange/improvement/apache-adaptor-logging

Improve Apache adaptor error message when it's not possible to write to the log

Utilities/Adaptors/Adaptor/log.c

@@ -213,6 +213,7 @@ void WOLog(int level, const char *format, ...)
       strftime(timestamp, sizeof(timestamp), "%d-%b-%Y %T - ", t);
       WA_unlock(logMutex);
 #endif
+      errno = 0;
       log = fopen(logPath, "a+");
       if (log != NULL) {
 #if defined(TIMESTAMP_LOG_MESSAGES)
@@ -227,7 +228,7 @@ void WOLog(int level, const char *format, ...)
       }else{
 // TODO - figure out how to report this for other web servers
 #if defined(APACHE)
-         ap_log_error(APLOG_MARK, APLOG_ERR, 0, _webobjects_server, "Failed to append to log file '%s'.  This can occur when the file is not writable by the child httpd process.  A workaround is to change the ownership of the file to match the child httpd process.", logPath);
+         ap_log_error(APLOG_MARK, APLOG_ERR, 0, _webobjects_server, "Failed to append to log file '%s': %s. This can occur when the file is not writable by the child httpd process. A workaround is to change the file ownership to match the child httpd process. Beware that other restrictions may apply when running Apache using systemd with the PrivateTmp option active.", logPath, strerror(errno));
 #endif
       }
    }