activity: clarifying 'all' read cases

desk/app/activity.hoon

@@ -662,27 +662,40 @@
     (refresh-index source index(items.reads read-items) &)
   ::
       %all
-    =/  new=index:a
-      ::  if we're only marking at our level, then we only want to grab
-      ::  read items from our level, because we can't move the floor in
-      ::  case children have older unread items
-      ?:  !deep.action
+    ?:  !deep.action
+      =/  new=index:a
+        ::  take every event between the floor and now, and put it into
+        ::  the index's items.reads. this way, the floor can be moved
+        ::  without "losing" any unreads, and the call to +refresh-index
+        ::  below will clean up unnecessary items.reads entries.
+        ::
         =-  index(items.reads (malt -))
         %+  murn
           %-  tap:on-event:a
           (lot:on-event:a stream.index `floor.reads.index ~)
         |=  [=time =event:a]
         ?:  child.event  ~
         `[time ~]
-      ::  otherwise, we can short circuit and just mark everything read,
-      ::  because we're going to also mark all children read
+      ::  we need to refresh our own index to reflect new reads
+      =.  cor  (refresh-index source new &)
+      ::  since we're not marking deep, we already have the items to
+      ::  send up to parents
+      %+  propagate-read-items  source
+      (tap:on-read-items:a items.reads.new)
+    ::
+    ::  marking read "deeply"
+    ::
+    =/  new=index:a
+      ::  we can short circuit and just mark everything read, because
+      ::  we're going to also mark all children read
       =-  index(reads [- ~])
       ?^  time.action  u.time.action
       =/  latest=(unit [=time event:a])
         (ram:on-event:a stream.index)
       ?~(latest now.bowl time.u.latest)
-    ::  if we're marking deep then we need to recursively read all children
-    =?  cor  deep.action
+    ::  since we're marking deeply we need to recursively read all
+    ::  children
+    =.  cor
       =/  children  (get-children source)
       |-
       ?~  children  cor
@@ -691,21 +704,19 @@
       $(children t.children)
     ::  we need to refresh our own index to reflect new reads
     =.  cor  (refresh-index source new &)
-    ::  if this isn't a recursive read, we need to propagate the new read
-    ::  items up the tree so that parents can keep accurate counts
-    =?  cor  !from-parent
-      %+  propagate-read-items  source
-      ::  if we're not marking deep, we already have the items to send up
-      ?:  !deep.action  (tap:on-read-items:a items.reads.new)
-      ::  if not, we need to generate the new items based on the floor
-      ::  we just came up with
-      %+  turn
-        %-  tap:on-event:a
-        %^  lot:on-event:a  stream.index  `floor.reads.index
-        ?:((gte floor.reads.new floor.reads.index) `+(floor.reads.new) ~)
-      |=  [=time-id:a *]
-      [time-id ~]
-    cor
+    ::  if this isn't a recursive read (see 4 lines above), we need to
+    ::  propagate the new read items up the tree so that parents can
+    ::  keep accurate counts, otherwise we can no-op
+    ?:  from-parent  cor
+    %+  propagate-read-items  source
+    ::  if not, we need to generate the new items based on the floor
+    ::  we just came up with
+    %+  turn
+      %-  tap:on-event:a
+      %^  lot:on-event:a  stream.index  `floor.reads.index
+      ?:((gte floor.reads.new floor.reads.index) `+(floor.reads.new) ~)
+    |=  [=time-id:a *]
+    [time-id ~]
   ==
 ::
 ++  propagate-read-items