diff --git a/lib/storage/file.js b/lib/storage/file.js
index 172ed8e1a..25ff021f0 100644
--- a/lib/storage/file.js
+++ b/lib/storage/file.js
@@ -11,6 +11,7 @@ var Meta = require("../metadata");
 var Extras = require("../hk-util");
 
 const readFileBin = require("../stream-file").readFileBin;
+const BatchRead = require("../batch-read");
 
 const Schedule = require("../schedule");
 const isValidChannelId = function (id) {
@@ -62,7 +63,7 @@ const destroyStream = function (stream) {
     if (!stream) { return; }
     try { stream.close(); } catch (err) { console.error(err); }
     setTimeout(function () {
-        try { stream.destroy(); } catch (err) { console.log(err); }
+        try { stream.destroy(); } catch (err) { console.error(err); }
     }, 5000);
 };
 
@@ -142,7 +143,6 @@ var closeChannel = function (env, channelName, cb) {
             destroyStream(stream, channelName);
         }
         delete env.channels[channelName];
-        env.openFiles--;
         cb();
     } catch (err) {
         cb(err);
@@ -291,7 +291,7 @@ var writeMetadata = function (env, channelId, data, cb) {
 
 
 // check if a file exists at $path
-var checkPath = function (path, callback) {
+var checkPath = function (path, callback) { // callback's second arg is never used...
     Fs.stat(path, function (err) {
         if (!err) {
             callback(undefined, true);
@@ -633,7 +633,7 @@ var unarchiveChannel = function (env, channelName, cb) {
         }));
     });
 };
-
+/*
 var flushUnusedChannels = function (env, cb, frame) {
     var currentTime = +new Date();
 
@@ -655,6 +655,7 @@ var flushUnusedChannels = function (env, cb, frame) {
     });
     cb();
 };
+*/
 
 /*  channelBytes
     calls back with an error or the size (in bytes) of a channel and its metadata
@@ -687,106 +688,63 @@ var channelBytes = function (env, chanName, cb) {
     });
 };
 
-/*::
-export type ChainPadServer_ChannelInternal_t = {
-    atime: number,
-    writeStream: typeof(process.stdout),
-    whenLoaded: ?Array<(err:?Error, chan:?ChainPadServer_ChannelInternal_t)=>void>,
-    onError: Array<(?Error)=>void>,
-    path: string
-};
-*/
-var getChannel = function ( // XXX BatchRead
-    env,
-    id,
-    _callback /*:(err:?Error, chan:?ChainPadServer_ChannelInternal_t)=>void*/
-) {
-    //console.log("getting channel [%s]", id);
-    var callback = Util.once(Util.mkAsync(_callback));
+var getChannel = function (env, id, _callback) {
+    var cb = Util.once(Util.mkAsync(_callback));
+
+    // if the channel is in memory
     if (env.channels[id]) {
         var chan = env.channels[id];
-        chan.atime = +new Date();
-        if (chan.whenLoaded) {
-            chan.whenLoaded.push(callback);
-        } else {
-            callback(undefined, chan);
-        }
-        return;
+        // delay its pending close a little longer
+        chan.delayClose();
+        // and return its writeStream
+        return void cb(void 0, chan);
     }
 
-    if (env.openFiles >= env.openFileLimit) {
-        // FIXME warn if this is the case?
-        // alternatively use graceful-fs to handle lots of concurrent reads
-        // if you're running out of open files, asynchronously clean up expired files
-        // do it on a shorter timeframe, though (half of normal)
-        setTimeout(function () {
-            //console.log("FLUSHING UNUSED CHANNELS");
-            flushUnusedChannels(env, function () {
-                if (env.verbose) {
-                    console.log("Approaching open file descriptor limit. Cleaning up");
+    // otherwise you need to open it or wait until its pending open completes
+    return void env.batchGetChannel(id, cb, function (done) {
+        var path = mkPath(env, id);
+        var channel = {
+            onError: [],
+        };
+        nThen(function (w) {
+            // create the path to the file if it doesn't exist
+            checkPath(path, w(function (err) {
+                if (err) {
+                    w.abort();
+                    return void done(err);
                 }
-            }, env.channelExpirationMs / 2);
-        });
-    }
-    var path = mkPath(env, id);
-    var channel /*:ChainPadServer_ChannelInternal_t*/ = env.channels[id] = {
-        atime: +new Date(),
-        writeStream: (undefined /*:any*/),
-        whenLoaded: [ callback ],
-        onError: [ ],
-        path: path
-    };
-    var complete = function (err) {
-        var whenLoaded = channel.whenLoaded;
-        // no guarantee stream.on('error') will not cause this to be called multiple times
-        if (!whenLoaded) { return; }
-        channel.whenLoaded = undefined;
-        if (err) {
-            delete env.channels[id];
-        }
-        if (!channel.writeStream) {
-            throw new Error("getChannel() complete called without channel writeStream"); // XXX
-        }
-        whenLoaded.forEach(function (wl) { wl(err, (err) ? undefined : channel); });
-    };
-    var fileExists;
-    nThen(function (waitFor) {
-        checkPath(path, waitFor(function (err, exists) {
-            if (err) {
-                waitFor.abort();
-                return void complete(err);
-            }
-            fileExists = exists;
-        }));
-    }).nThen(function (waitFor) {
-        var stream = channel.writeStream = Fs.createWriteStream(path, { flags: 'a' }); // XXX
-        env.openFiles++;
-        stream.on('open', waitFor());
-        stream.on('error', function (err /*:?Error*/) {
-            env.openFiles--;
-            // this might be called after this nThen block closes.
-            if (channel.whenLoaded) {
-                complete(err);
-            } else {
+            }));
+        }).nThen(function (w) {
+            var stream = channel.writeStream = Fs.createWriteStream(path, { flags: 'a' });
+            stream.on('open', w());
+            stream.on('error', function (err) {
+                w.abort();
+                // this might be called after this nThen block closes.
                 channel.onError.forEach(function (handler) {
                     handler(err);
                 });
-            }
+            });
+        }).nThen(function () {
+            channel.delayClose = Util.throttle(function () {
+                delete env.channels[id];
+                destroyStream(channel.writeStream, path);
+                //console.log("closing writestream");
+            }, 30000);
+            channel.delayClose();
+            env.channels[id] = channel;
+            done(void 0, channel);
         });
-    }).nThen(function () {
-        complete();
     });
 };
 
 // write a message to the disk as raw bytes
 const messageBin = (env, chanName, msgBin, cb) => {
     var complete = Util.once(cb);
-    getChannel(env, chanName, function (err, chan) { // XXX
+    getChannel(env, chanName, function (err, chan) {
         if (!chan) { return void complete(err); }
         chan.onError.push(complete);
         chan.writeStream.write(msgBin, function () {
             chan.onError.splice(chan.onError.indexOf(complete), 1);
-            chan.atime = +new Date(); // XXX we should just throttle closing, much simpler and less error prone
             complete();
         });
     });
@@ -1000,8 +958,7 @@ module.exports.create = function (conf, cb) {
         channels: { },
         channelExpirationMs: conf.channelExpirationMs || 30000,
         verbose: conf.verbose,
-        openFiles: 0,
-        openFileLimit: conf.openFileLimit || 2048,
+        batchGetChannel: BatchRead('store_batch_channel'),
     };
     var it;
 
@@ -1240,7 +1197,8 @@ module.exports.create = function (conf, cb) {
             },
             // iterate over open channels and close any that are not active
             flushUnusedChannels: function (cb) {
-                flushUnusedChannels(env, cb);
+                cb("DEPRECATED");
+                //flushUnusedChannels(env, cb);
             },
             // write to a log file
             log: function (channelName, content, cb) {
@@ -1255,7 +1213,8 @@ module.exports.create = function (conf, cb) {
             }
         });
     });
+    /*
     it = setInterval(function () {
         flushUnusedChannels(env, function () { });
-    }, 5000);
+    }, 5000);*/
 };
diff --git a/www/admin/inner.js b/www/admin/inner.js
index ad7083c6c..acc789784 100644
--- a/www/admin/inner.js
+++ b/www/admin/inner.js
@@ -43,6 +43,7 @@ define([
         'stats': [
             'cp-admin-active-sessions',
             'cp-admin-active-pads',
+            'cp-admin-open-files',
             'cp-admin-registered',
             'cp-admin-disk-usage',
         ],
@@ -119,6 +120,17 @@ define([
         });
         return $div;
     };
+    create['open-files'] = function () {
+        var key = 'open-files'; // XXX
+        var $div = makeBlock(key);
+        sFrameChan.query('Q_ADMIN_RPC', {
+            cmd: 'GET_FILE_DESCRIPTOR_COUNT',
+        }, function (e, data) {
+            console.log(e, data);
+            $div.append(h('pre', String(data)));
+        });
+        return $div;
+    };
     create['registered'] = function () {
         var key = 'registered';
         var $div = makeBlock(key);
diff --git a/www/common/common-ui-elements.js b/www/common/common-ui-elements.js
index f8a3711c0..fefbba6e1 100644
--- a/www/common/common-ui-elements.js
+++ b/www/common/common-ui-elements.js
@@ -803,6 +803,17 @@ define([
             var chan = [data.channel];
             if (data.rtChannel) { chan.push(data.rtChannel); }
             if (data.lastVersion) { chan.push(Hash.hrefToHexChannelId(data.lastVersion)); }
+            var channels = chan.filter(function (c) { return c.length === 32; }).map(function (id) {
+                if (id === data.rtChannel && data.lastVersion && data.lastCpHash) {
+                    return {
+                        channel: id,
+                        lastKnownHash: data.lastCpHash
+                    };
+                }
+                return {
+                    channel: id
+                };
+            });
             var history = common.makeUniversal('history');
             var trimChannels = [];
             NThen(function (waitFor) {
@@ -819,7 +830,7 @@ define([
                 if (!owned) { return; }
                 history.execCommand('GET_HISTORY_SIZE', {
                     pad: true,
-                    channels: chan.filter(function (c) { return c.length === 32; }),
+                    channels: channels,
                     teamId: typeof(owned) === "number" && owned
                 }, waitFor(function (obj) {
                     if (obj && obj.error) { return; }
diff --git a/www/common/drive-ui.js b/www/common/drive-ui.js
index 50506f248..c039a86e3 100644
--- a/www/common/drive-ui.js
+++ b/www/common/drive-ui.js
@@ -259,12 +259,14 @@ define([
     };
 
     // Handle disconnect/reconnect
-    var setEditable = function (state) {
+    var setEditable = function (state, isHistory) {
         if (APP.closed || !APP.$content || !$.contains(document.documentElement, APP.$content[0])) { return; }
         APP.editable = !APP.readOnly && state;
         if (!state) {
             APP.$content.addClass('cp-app-drive-readonly');
-            $('#cp-app-drive-connection-state').show();
+            if (!isHistory) {
+                $('#cp-app-drive-connection-state').show();
+            }
             $('[draggable="true"]').attr('draggable', false);
         }
         else {
@@ -3865,6 +3867,7 @@ define([
 
             var opts = {};
             opts.href = Hash.getRelativeHref(data.href || data.roHref);
+            opts.channel = data.channel;
 
             if (manager.isSharedFolder(el)) {
                 var ro = folders[el] && folders[el].version >= 2;
diff --git a/www/common/onlyoffice/inner.js b/www/common/onlyoffice/inner.js
index 0ad29df6c..5ac3da269 100644
--- a/www/common/onlyoffice/inner.js
+++ b/www/common/onlyoffice/inner.js
@@ -104,10 +104,14 @@ define([
             return metadataMgr.getNetfluxId() + '-' + privateData.clientId;
         };
 
+        var getEditor = function () {
+            return window.frames[0].editor || window.frames[0].editorCell;
+        };
+
         var setEditable = function (state) {
             $('#cp-app-oo-editor').find('#cp-app-oo-offline').remove();
             try {
-                window.frames[0].editor.asc_setViewMode(!state);
+                getEditor().asc_setViewMode(!state);
                 //window.frames[0].editor.setViewModeDisconnect(true);
             } catch (e) {}
             if (!state && !readOnly) {
@@ -241,10 +245,6 @@ define([
             cpIndex: 0
         };
 
-        var getEditor = function () {
-            return window.frames[0].editor || window.frames[0].editorCell;
-        };
-
         var getContent = function () {
             try {
                 return getEditor().asc_nativeGetFile();
@@ -325,6 +325,7 @@ define([
             body: $('body'),
             onUploaded: function (ev, data) {
                 if (!data || !data.url) { return; }
+                data.hash = ev.hash;
                 sframeChan.query('Q_OO_SAVE', data, function (err) {
                     onUploaded(ev, data, err);
                 });
@@ -846,7 +847,7 @@ define([
                         "id": String(myOOId), //"c0c3bf82-20d7-4663-bf6d-7fa39c598b1d",
                         "firstname": metadataMgr.getUserData().name || Messages.anonymous,
                     },
-                    "mode": readOnly || lock ? "view" : "edit",
+                    "mode": lock ? "view" : "edit",
                     "lang": (navigator.language || navigator.userLanguage || '').slice(0,2)
                 },
                 "events": {
@@ -1556,6 +1557,7 @@ define([
                 content = hjson.content || content;
                 var newLatest = getLastCp();
                 sframeChan.query('Q_OO_SAVE', {
+                    hash: newLatest.hash,
                     url: newLatest.file
                 }, function () { });
                 newDoc = !content.hashes || Object.keys(content.hashes).length === 0;
@@ -1649,6 +1651,7 @@ define([
                 var newLatest = getLastCp();
                 if (newLatest.index > latest.index) {
                     sframeChan.query('Q_OO_SAVE', {
+                        hash: newLatest.hash,
                         url: newLatest.file
                     }, function () { });
                 }
diff --git a/www/common/onlyoffice/main.js b/www/common/onlyoffice/main.js
index 7007bd360..9096cd730 100644
--- a/www/common/onlyoffice/main.js
+++ b/www/common/onlyoffice/main.js
@@ -61,6 +61,7 @@ define([
                     if (e) { return void cb(e); }
                     Cryptpad.setPadAttribute('lastVersion', data.url, cb);
                 });
+                Cryptpad.setPadAttribute('lastCpHash', data.hash, cb);
             });
             sframeChan.on('Q_OO_OPENCHANNEL', function (data, cb) {
                 Cryptpad.getPadAttribute('rtChannel', function (err, res) {
diff --git a/www/common/outer/onlyoffice.js b/www/common/outer/onlyoffice.js
index 968ea12c3..567bc180b 100644
--- a/www/common/outer/onlyoffice.js
+++ b/www/common/outer/onlyoffice.js
@@ -36,6 +36,7 @@ define([
             return void cb();
         }
 
+        var txid = Math.floor(Math.random() * 1000000);
         var onOpen = function (wc) {
 
             ctx.channels[channel] = ctx.channels[channel] || {
@@ -91,6 +92,7 @@ define([
 
             var hk = network.historyKeeper;
             var cfg = {
+                txid: txid,
                 lastKnownHash: chan.lastKnownHash || chan.lastCpHash,
                 metadata: {
                     validateKey: obj.validateKey,
@@ -121,6 +123,8 @@ define([
             } catch (e) {}
             if (!parsed) { return; }
 
+            // If there is a txid, make sure it's ours or abort
+            if (parsed.txid && parsed.txid !== txid) { return; }
 
             // Keep only metadata messages for the current channel
             if (parsed.channel && parsed.channel !== channel) { return; }
@@ -138,6 +142,11 @@ define([
             }
             if (parsed.error && parsed.channel) { return; }
 
+            // If there is a txid, make sure it's ours or abort
+            if (Array.isArray(parsed) && parsed[0] && parsed[0] !== txid) {
+                return;
+            }
+
             msg = parsed[4];
 
             // Keep only the history for our channel
diff --git a/www/common/outer/profile.js b/www/common/outer/profile.js
index dd56db6e9..733b2b4c4 100644
--- a/www/common/outer/profile.js
+++ b/www/common/outer/profile.js
@@ -54,6 +54,9 @@ define([
             if (!lm.proxy.notifications) {
                 lm.proxy.notifications = Util.find(ctx.store.proxy, ['mailboxes', 'notifications', 'channel']);
             }
+            if (!lm.proxy.edPublic) {
+                lm.proxy.edPublic = ctx.store.proxy.edPublic;
+            }
             if (ctx.onReadyHandlers.length) {
                 ctx.onReadyHandlers.forEach(function (f) {
                     try {
diff --git a/www/common/userObject.js b/www/common/userObject.js
index db8e687d3..b11bcf4b1 100644
--- a/www/common/userObject.js
+++ b/www/common/userObject.js
@@ -203,7 +203,6 @@ define([
             var base = exp.getStructure();
             return typeof (obj) === "object" &&
                     Object.keys(base).every(function (key) {
-                        console.log(key, obj[key], type(obj[key]));
                         return obj[key] && type(base[key]) === type(obj[key]);
                     });
         };
diff --git a/www/drive/inner.js b/www/drive/inner.js
index f5251f284..720ac562d 100644
--- a/www/drive/inner.js
+++ b/www/drive/inner.js
@@ -119,7 +119,7 @@ define([
 
     var setHistory = function (bool, update) {
         history.isHistoryMode = bool;
-        setEditable(!bool);
+        setEditable(!bool, true);
         if (!bool && update) {
             history.onLeaveHistory();
         }
diff --git a/www/profile/inner.js b/www/profile/inner.js
index 9626c7734..5dfbaf491 100644
--- a/www/profile/inner.js
+++ b/www/profile/inner.js
@@ -457,6 +457,34 @@ define([
         APP.editor.save();
     };
 
+    Messages.profile_copyKey = "Copy edPublic key"; // XXX
+    var addPublicKey = function ($container) {
+        if (!APP.readOnly) { return; }
+
+        var $div = $(h('div.cp-sidebarlayout-element')).appendTo($container);
+        APP.$edPublic = $('<button>', {
+            'class': 'btn btn-success',
+        }).append(h('i.fa.fa-key'))
+          .append(h('span', Messages.profile_copyKey))
+          .click(function () {
+            if (!APP.getEdPublic) { return; }
+            APP.getEdPublic();
+        }).appendTo($div).hide();
+    };
+    var setPublicKeyButton = function (data) {
+        if (!data.edPublic || APP.getEdPublic || !APP.readOnly) { return; }
+        APP.$edPublic.show();
+        APP.getEdPublic = function () {
+            var metadataMgr = APP.common.getMetadataMgr();
+            var privateData = metadataMgr.getPrivateData();
+            var name = data.name.toLowerCase().replace(/[^a-zA-Z0-9]+/g, "-");
+            var ed = data.edPublic.replace(/\//g, '-');
+            var url = privateData.origin + '/user/#/1/' + name + '/' + ed;
+            var success = Clipboard.copy(url);
+            if (success) { UI.log(Messages.shareSuccess); }
+        };
+    };
+
     var createLeftside = function () {
         var $categories = $('<div>', {'class': 'cp-sidebarlayout-categories'}).appendTo(APP.$leftside);
         var $category = $('<div>', {'class': 'cp-sidebarlayout-category'}).appendTo($categories);
@@ -477,6 +505,7 @@ define([
             addFriendRequest($rightside);
             addMuteButton($rightside);
             addDescription(APP.$rightside);
+            addPublicKey(APP.$rightside);
             addViewButton($rightside);
             APP.initialized = true;
             createLeftside();
@@ -490,6 +519,7 @@ define([
         refreshDescription(data);
         refreshFriendRequest(data);
         refreshMute(data);
+        setPublicKeyButton(data);
     };
 
     var createToolbar = function () {
diff --git a/www/whiteboard/app-whiteboard.less b/www/whiteboard/app-whiteboard.less
index 0ac575df6..b715e188c 100644
--- a/www/whiteboard/app-whiteboard.less
+++ b/www/whiteboard/app-whiteboard.less
@@ -35,7 +35,6 @@
     #cp-app-whiteboard-container {
         flex: 1;
         display: flex;
-        flex-flow: column;
         overflow: auto;
     }
 
@@ -43,14 +42,17 @@
     #cp-app-whiteboard-canvas-area {
         flex: 1;
         display: flex;
+        min-height: 0;
     }
     // created by fabricjs. styled so defaults don't break anything
     .cp-app-whiteboard-canvas-container {
+        width: 100%;
         margin: auto;
         background: white;
         flex: 1;
         min-height: 0;
         & > canvas {
+            width: 100%;
             border: 1px solid black;
         }
     }
diff --git a/www/whiteboard/inner.js b/www/whiteboard/inner.js
index 77057f505..2c3125903 100644
--- a/www/whiteboard/inner.js
+++ b/www/whiteboard/inner.js
@@ -137,7 +137,7 @@ define([
                 canvas.discardActiveGroup();
             }
             canvas.renderAll();
-            framework.localChange();
+            APP.onLocal();
         };
         $deleteButton.click(deleteSelection);
         $(window).on('keyup', function (e) {
@@ -220,7 +220,7 @@ define([
             var metadata = JSON.parse(JSON.stringify(metadataMgr.getMetadata()));
             metadata.palette = newPalette;
             metadataMgr.updateMetadata(metadata);
-            framework.localChange();
+            APP.onLocal();
         };
 
         var makeColorButton = function ($container) {
@@ -284,6 +284,34 @@ define([
         });
         var $canvas = $('canvas');
         var $canvasContainer = $('canvas').parents('.cp-app-whiteboard-canvas-container');
+        var $container = $('#cp-app-whiteboard-container');
+
+        // Max for old macs: 2048×1464
+        // Max for IE: 8192x8192
+        var MAX = 8192;
+        var onResize = APP.onResize = function () {
+            var w = $container.width();
+            var h = $container.height();
+            canvas.forEachObject(function (obj) {
+                var c = obj.getCoords();
+                Object.keys(c).forEach(function (k) {
+                    if (c[k].x > w) { w = c[k].x + 1; }
+                    if (c[k].y > h) { h = c[k].y + 1; }
+                });
+            });
+            w = Math.min(w, MAX);
+            h = Math.min(h, MAX);
+            canvas.setWidth(w);
+            canvas.setHeight(h);
+            canvas.calcOffset();
+        };
+        $(window).on('resize', onResize);
+
+        var onLocal = APP.onLocal = function () {
+            framework.localChange();
+            APP.onResize();
+        };
+
         var $controls = $('#cp-app-whiteboard-controls');
         var metadataMgr = framework._.cpNfInner.metadataMgr;
 
@@ -333,7 +361,7 @@ define([
             }
             var cImg = new Fabric.Image(img, { left:0, top:0, angle:0, });
             APP.canvas.add(cImg);
-            framework.localChange();
+            onLocal();
         };
 
         // Embed image
@@ -403,7 +431,7 @@ define([
 
         $('#cp-app-whiteboard-clear').on('click', function () {
             canvas.clear();
-            framework.localChange();
+            onLocal();
         });
 
         // ---------------------------------------------
@@ -432,6 +460,7 @@ define([
             var content = newContent.content;
             canvas.loadFromJSON(content, waitFor(function () {
                 canvas.renderAll();
+                onResize();
             }));
         });
 
@@ -461,7 +490,7 @@ define([
             window.setTimeout(mkThumbnail, Thumb.UPDATE_FIRST);
         });
 
-        canvas.on('mouse:up', framework.localChange);
+        canvas.on('mouse:up', onLocal);
         framework.start();
     };
 
@@ -471,8 +500,6 @@ define([
             h('div#cp-app-whiteboard-canvas-area',
                 h('div#cp-app-whiteboard-container',
                     h('canvas#cp-app-whiteboard-canvas', {
-                        width: 600,
-                        height: 600
                     })
                 )
             ),