int fNoHttpCompress;    /* Do not compress HTTP traffic (for debugging) */
  char *zSshCmd;          /* SSH command string */
  const char *zHttpCmd;   /* External program to do HTTP requests */
  int fNoSync;            /* Do not do an autosync ever.  --nosync */
  int fIPv4;              /* Use only IPv4, not IPv6. --ipv4 */
  char *zPath;            /* Name of webpage being served */
  char *zExtra;           /* Extra path information past the webpage name */
  char *zBaseURL;         /* Full URL for the toplevel of the fossil tree */
  const char *zUrlSuffix; /* Suffix of the URL including query string
     zBaseUrl/zUrlSuffix  == Full text of the URL being served */
  char *zHttpsURL;        /* zBaseURL translated to https: */
  char *zTop;             /* Parent directory of zPath */
  int nExtraURL;          /* Extra bytes added to SCRIPT_NAME */
  const char *zExtRoot;   /* Document root for the /ext sub-website */
  const char *zContentType;  /* The content type of the input HTTP request */
  int iErrPriority;       /* Priority of current error message */
  char *zErrMsg;          /* Text of an error message */

** g.zBaseURL and g.zTop is set from that instead.
*/
void set_base_url(const char *zAltBase){
  int i;
  const char *zHost;
  const char *zMode;
  const char *zCur;
  const char *zRU;     /* REQUEST_URI      */
  const char *zQS;     /* QUERY_STRING     */
  size_t nTop;         /* length of g.zTop */

  if( g.zBaseURL!=0 ) return;
  if( zAltBase ){
    int i, n, c;
    g.zTop = g.zBaseURL = mprintf("%s", zAltBase);
    i = (int)strlen(g.zBaseURL);
    while( i>3 && g.zBaseURL[i-1]=='/' ){ i--; }

      g.zBaseURL = mprintf("http://%s%.*s", z, i, zCur);
      g.zTop = &g.zBaseURL[7+strlen(z)];
      g.zHttpsURL = mprintf("https://%s%.*s", z, i, zCur);
    }
    fossil_free(z);
  }

  zRU  = PD("REQUEST_URI","");
  nTop = strlen( g.zTop );
  g.zUrlSuffix = strncmp(zRU,g.zTop,nTop) ? "" : zRU+nTop;
  if(g.zUrlSuffix[0]=='/') g.zUrlSuffix++;
  zQS  = PD("QUERY_STRING","");
  if( zQS[0] ) g.zUrlSuffix = mprintf("%s?%s", g.zUrlSuffix, zQS);
  else         g.zUrlSuffix = mprintf("%s",    g.zUrlSuffix);

  /* Try to record the base URL as a CONFIG table entry with a name
  ** of the form:  "baseurl:BASE".  This keeps a record of how the
  ** the repository is used as a server, to help in answering questions
  ** like "where is the CGI script that references this repository?"
  **
  ** This is just a logging hint.  So don't worry if it cannot be done.
  ** Don't try this if the repository database is not writable, for