listThreads can figure out the proper offset without some stupid

extra param.

Added getNewestMessagePerSub(grp) and getNewestMessageInSub(sub);
these do pretty much what you would guess, although maybe not
exactly because what is "message" anyway?

Added 'guest' mode to getThreadStats, since some stats (votes)
can be shown to guests, but others (unread messages) shouldn't.

webv4/lib/forum.js

@@ -45,15 +45,13 @@ function listSubs(group) {
     });
 }
 
-function listThreads(sub, offset, count, page_offset) {
+function listThreads(sub, offset, count) {
 
     offset = parseInt(offset);
     if (isNaN(offset) || offset < 0) return false;
     count = parseInt(count);
     if (isNaN(count) || count < 1) return false;
 
-    if (page_offset) offset = offset * count;
-
     var threads = getMessageThreads(sub, settings.max_messages);
     if (offset >= threads.order.length) return false;
 
@@ -72,6 +70,36 @@ function listThreads(sub, offset, count, page_offset) {
 
 }
 
+function getNewestMessageInSub(sub) {
+    const mb = new MsgBase(sub.code);
+    if (!mb.open()) return;
+    var h;
+    var ret;
+    for (var m = mb.last_msg; m >= mb.first_msg; m--) {
+        h = mb.get_msg_header(m);
+        if (h === null) continue;
+        ret = {
+            from: h.from,
+            subject: h.subject,
+            when_written_time: h.when_written_time,
+        };
+        break;
+    }
+    mb.close();
+    return ret;
+}
+
+function getNewestMessagePerSub(grp) {
+    grp = parseInt(grp, 10);
+    if (isNaN(grp) || grp < 0 || !msg_area.grp_list[grp]) return [];
+    return msg_area.grp_list[grp].sub_list.reduce(function (a, c) {
+        const s = getNewestMessageInSub(c);
+        if (s !== undefined) a[c.code] = s;
+        log(LOG_DEBUG, JSON.stringify(s));
+        return a;
+    }, {});
+}
+
 function getSubUnreadCount(sub) {
     var ret = {
         scanned: 0,
@@ -157,7 +185,7 @@ function getThreadVoteTotals(thread, mkeys) {
 }
 
 // { [thread_id]: { total, unread, votes: { up: { parent, total }, down: { parent, total }, total }, newest } }
-function getThreadStats(sub, offset, page_size) {
+function getThreadStats(sub, offset, page_size, guest) {
     const threads = getMessageThreads(sub, settings.max_messages);
     const ret = {};
     if (!offset) offset = 0;
@@ -169,7 +197,7 @@ function getThreadStats(sub, offset, page_size) {
         var mkeys = Object.keys(thread.messages);
         ret[threads.order[n]] = {
             total: mkeys.length,
-            unread: getUnreadInThread(sub, thread, mkeys),
+            unread: guest ? 0 : getUnreadInThread(sub, thread, mkeys),
             votes: getThreadVoteTotals(thread, mkeys),
             newest: {
                 from: thread.messages[mkeys[mkeys.length - 1]].from,