onload/onerror/beforesend/aftersend handlers of its own, this
   function falls to defaults which are member properties of this
   function with the same name, e.g. fossil.fetch.onload(). The
   default onload/onerror implementations route the data through the
   dev console and (for onerror()) through fossil.error(). The default
   beforesend/aftersend are no-ops. Individual pages may overwrite
   those members to provide default implementations suitable for the
   page's use, e.g. keeping track of how many in-flight ajax requests
   are pending. Any exceptions thrown in an beforesend/aftersend
   handler are current ignored (feature or bug?).

   Note that this routine may add properties to the 2nd argument, so
   that instance should not be kept around for later use.

   Returns this object, noting that the XHR request is asynchronous,
   and still in transit (or has yet to be sent) when that happens.
*/

           && P.wikiContent()){
          F.error("This new/unsaved page has content.",
                  "To really discard this page,",
                  "first clear its content",
                  "then use the Discard button.");
          return;
        }
        P.unstashContent();
        if(w.version || w.type==='sandbox'){
          P.loadPage(w);
        }else{
          WikiList.removeEntry(w.name);
          delete P.winfo;
          P.updatePageTitle();
          F.message("Discarded new page ["+w.name+"].");
        }
      },
      ticks: F.config.confirmerButtonTicks
    });
    F.confirmer(P.e.btnSave, {
      confirmText: "Really save changes?",
      onconfirm: function(e){
        const w = P.winfo;
        if(!w){
          F.error("No page loaded.");
          return;
        }
        setTimeout(
          ()=>P.save(), 0
          /* timeout is a workaround to allow save() to update the
             button's text (per forum feedback).  The idea is to force
             the call of save() to happen *after* the confirmer
             callback returns so that we can change the button label
             without the confirmer setting it back to its
             pre-confirmed state. This is, however, no guaranty that
             save() will actually be called *after* the confirmer
             re-sets the button label. */
        );
      },
      ticks: F.config.confirmerButtonTicks
    });

    P.e.taEditor.addEventListener(
      'change', ()=>P.stashContentChange(), false
    );

        P.e.selectMimetype.value = winfo.mimetype;
        P.tabs.switchToTab(P.e.tabs.content);
        P.wikiContent(winfo.content || '');
        WikiList.e.select.value = winfo.name;
        if(!winfo.version && winfo.type!=='sandbox'){
          F.message('You are editing a new, unsaved page:',winfo.name);
        }
        P.updatePageTitle().updateSaveButton(/* b/c save() routes through here */);
      },
      false
    );
    /* These init()s need to come after P's event handlers are registered */
    WikiList.init( P.e.tabs.pageList.firstElementChild );
    P.stashWidget.init(P.e.tabs.content.lastElementChild);
    //P.$wikiList = WikiList/*only for testing/debugging*/;

  /**
     Saves the current wiki page and re-populates the editor
     with the saved state.
  */
  P.save = function callee(){
    if(!affirmPageLoaded()) return this;

    const content = this.wikiContent();
    if(!callee.onload){
      const self = this;
      callee.onload = function(w){
        const oldWinfo = self.winfo;
        self.unstashContent(oldWinfo);
        self.dispatchEvent('wiki-page-loaded', w);
        F.message("Saved page: ["+w.name+"].");
      }
    }
    const fd = new FormData(), w = P.winfo;
    fd.append('page',w.name);
    fd.append('mimetype', w.mimetype);
    fd.append('isnew', w.version ? 0 : 1);
    fd.append('content', P.wikiContent());
    F.message(
      "Saving page..."
    ).fetch('wikiajax/save',{
      payload: fd,
      responseType: 'json',
      beforesend: function(){
        D.disable(P.e.btnSave);
        P.e.btnSave.innerText = "Saving...";
        F.fetch.beforesend();
      },
      onload: callee.onload
    });
    return this;
  };
  
  /**
     Updates P.winfo for certain state and stashes P.winfo, with the