** directly from disk and need not be a managed file.
**
** The "ckout" CHECKIN is intended for development - to provide a mechanism
** for looking at what a file will look like using the /doc webpage after
** it gets checked in.
**
** The file extension is used to decide how to render the file.
**
** If FILE ends in "/" then names "FILE/index.html", "FILE/index.wiki",
** and "FILE/index.md" are  in that order.  If none of those are found,
** then FILE is completely replaced by "404.md" and tried.  If that is
** not found, then a default 404 screen is generated.
*/
void doc_page(void){
  const char *zName;                /* Argument to the /doc page */
  const char *zOrigName;            /* Original document name */
  const char *zMime;                /* Document MIME type */
  char *zCheckin;                   /* The checkin holding the document */
  int vid = 0;                      /* Artifact of checkin */
  int rid = 0;                      /* Artifact of file */
  int i;                            /* Loop counter */
  Blob filebody;                    /* Content of the documentation file */
  int nMiss = 0;                    /* Failed attempts to find the document */
  static const char *azSuffix[] = {
     "index.html", "index.wiki", "index.md"
  };

  login_check_credentials();
  if( !g.perm.Read ){ login_needed(); return; }
  for(nMiss=0; rid==0 && nMiss<=ArraySize(azSuffix); nMiss++){
    zName = PD("name", "tip/index.wiki");
    for(i=0; zName[i] && zName[i]!='/'; i++){}
    zCheckin = mprintf("%.*s", i, zName);
    if( fossil_strcmp(zCheckin,"ckout")==0 && db_open_local(0)==0 ){
      zCheckin = "tip";
    }
    if( nMiss==ArraySize(azSuffix) ){
      zName = "404.md";
    }else if( zName[i]==0 ){
      zName = azSuffix[nMiss];
    }else{
      zName += i;
    }
    while( zName[0]=='/' ){ zName++; }
    g.zPath = mprintf("%s/%s/%s", g.zPath, zCheckin, zName);
    if( nMiss==0 ) zOrigName = zName;
    if( !file_is_simple_pathname(zName, 1) ){
      if( sqlite3_strglob("*/", zName)==0 ){
        zName = mprintf("%s%s", zName, azSuffix[nMiss]);
        if( !file_is_simple_pathname(zName, 1) ){
          goto doc_not_found;
        }
      }else{
        goto doc_not_found;
      }
    }



    if( fossil_strcmp(zCheckin,"ckout")==0 ){
      /* Read from the local checkout */
      char *zFullpath;
      db_must_be_within_tree();

      zFullpath = mprintf("%s/%s", g.zLocalRoot, zName);
      if( file_isfile(zFullpath)
       && blob_read_from_file(&filebody, zFullpath)>0 ){
        rid = 1;  /* Fake RID just to get the loop to end */
      }
      fossil_free(zFullpath);




    }else{
      db_begin_transaction();
      vid = name_to_typed_rid(zCheckin, "ci");
      db_multi_exec(
        "CREATE TABLE IF NOT EXISTS vcache(\n"
        "  vid INTEGER,         -- checkin ID\n"
        "  fname TEXT,          -- filename\n"
        "  rid INTEGER,         -- artifact ID\n"
        "  PRIMARY KEY(vid,fname)\n"
        ") WITHOUT ROWID"
      );
      if( !db_exists("SELECT 1 FROM vcache WHERE vid=%d", vid) ){
        db_multi_exec(
          "DELETE FROM vcache;\n"
          "CREATE VIRTUAL TABLE temp.foci USING files_of_checkin;\n"
          "INSERT INTO vcache(vid,fname,rid)"
          "  SELECT checkinID, filename, blob.rid FROM foci, blob"
          "   WHERE blob.uuid=foci.uuid"
          "     AND foci.checkinID=%d;",
          vid
        );
      }

      rid = db_int(0, "SELECT rid FROM vcache"
                      " WHERE vid=%d AND fname=%Q", vid, zName);

      nMiss++;


      if( rid==0 || content_get(rid, &filebody)==0 ){
        goto doc_not_found;
      }
      db_end_transaction(0);
    }
  }
  if( rid==0 ) goto doc_not_found;
  blob_to_utf8_no_bom(&filebody, 0);

  /* The file is now contained in the filebody blob.  Deliver the
  ** file to the user
  */
  zMime = nMiss==0 ? P("mimetype") : 0;
  if( zMime==0 ){