Fossil

                  " AND (SELECT value FROM tagxref WHERE tagid=tag.tagid"
                  " ORDER BY mtime DESC LIMIT 1) > 0", zTarget))
  ){
    return zTarget;
  }
  return 0;
}

static const char *wikiOverrideHash = 0;

/*
** Fossil-wiki hyperlinks to wiki pages should be overridden to the
** hash value supplied.  If the value is NULL, then override is cancelled
** and all overwrites operate normally.
*/
void wiki_hyperlink_override(const char *zUuid){
  wikiOverrideHash = zUuid;
}


/*
** If links to wiki page zTarget should be redirected to some historical
** version of that page, then return the hash of the historical version.
** If no override is required, return NULL.
*/
static const char *wiki_is_overridden(const char *zTarget){
  if( wikiOverrideHash==0 ) return 0;
  /* The override should only happen if the override version is not the
  ** latest version of the wiki page. */
  if( !db_exists(
    "SELECT 1 FROM tag, blob, tagxref AS xA, tagxref AS xB "
    " WHERE tag.tagname GLOB 'wiki-%q*'"
    "   AND blob.uuid GLOB '%q'"
    "   AND xA.tagid=tag.tagid AND xA.rid=blob.rid"
    "   AND xB.tagid=tag.tagid AND xB.mtime>xA.mtime",
    zTarget, wikiOverrideHash
  ) ){
    return 0;
  }
  return wikiOverrideHash;
}

/*
** Resolve a hyperlink.  The zTarget argument is the content of the [...]
** in the wiki.  Append to the output string whatever text is appropriate
** for opening the hyperlink.  Write into zClose[0...nClose-1] text that will
** close the markup.
**

    }else{
      zTerm = "";
    }
  }else if( strlen(zTarget)>=10 && fossil_isdigit(zTarget[0]) && zTarget[4]=='-'
            && db_int(0, "SELECT datetime(%Q) NOT NULL", zTarget) ){
    blob_appendf(p->pOut, "<a href=\"%R/timeline?c=%T\">", zTarget);
  }else if( (z = validWikiPageName(p, zTarget))!=0 ){
    const char *zOverride = wiki_is_overridden(zTarget);
    if( zOverride ){
      blob_appendf(p->pOut, "<a href=\"%R/info/%S\">", zOverride);
    }else{
      blob_appendf(p->pOut, "<a href=\"%R/wiki?name=%T\">", z);
    }
  }else if( zTarget>=&zOrig[2] && !fossil_isspace(zTarget[-2]) ){
    /* Probably an array subscript in code */
    zTerm = "";
  }else if( (p->state & (WIKI_NOBADLINKS|WIKI_LINKSONLY))!=0 ){
    zTerm = "";
  }else{
    blob_appendf(p->pOut, "<span class=\"brokenlink\">[%h]", zTarget);