diff --git a/.ci/install.sh b/.ci/install.sh
index b3bef371b..7771e4ee6 100755
--- a/.ci/install.sh
+++ b/.ci/install.sh
@@ -17,9 +17,7 @@ echo "wrap_bin_scripts = false" >> $HOME/.luarocks/config.lua
 travis_retry luarocks --local install luafilesystem
 # for verbose_print module
 travis_retry luarocks --local install ansicolors
-travis_retry luarocks --local install busted 2.0.rc11-0
-travis_retry luarocks --local remove lua_cliargs --force
-travis_retry luarocks --local install lua_cliargs 2.5-5 --force
+travis_retry luarocks --local install busted 2.0.rc12-1
 #- mv -f $HOME/.luarocks/bin/busted_bootstrap $HOME/.luarocks/bin/busted
 travis_retry luarocks --local install luacov
 # luasec doesn't automatically detect 64-bit libs
diff --git a/.ci/script.sh b/.ci/script.sh
index 5589e5e7a..2c1bfc48c 100755
--- a/.ci/script.sh
+++ b/.ci/script.sh
@@ -5,7 +5,7 @@ source "${CI_DIR}/common.sh"
 
 travis_retry make fetchthirdparty
 make all
-retry_cmd 2 make testfront
+make testfront
 set +o pipefail
 luajit $(which luacheck) --no-color -q frontend | tee ./luacheck.out
 test $(grep Total ./luacheck.out | awk '{print $2}') -le 19
diff --git a/Makefile b/Makefile
index ba2491865..bebcee2b2 100644
--- a/Makefile
+++ b/Makefile
@@ -98,7 +98,10 @@ $(INSTALL_DIR)/koreader/.luacov:
 		ln -sf ../../.luacov $(INSTALL_DIR)/koreader
 
 testfront: $(INSTALL_DIR)/koreader/.busted
+	# sdr files may have unexpected impact on unit testing
+	rm -rf spec/unit/data/*.sdr
 	cd $(INSTALL_DIR)/koreader && ./luajit $(shell which busted) \
+		--sort-files \
 		--no-auto-insulate \
 		-o verbose_print --exclude-tags=notest
 
diff --git a/base b/base
index d33be25e6..a57567246 160000
--- a/base
+++ b/base
@@ -1 +1 @@
-Subproject commit d33be25e6ad412bb98a6fa2ac3edf5f26d36c8ca
+Subproject commit a57567246963a561585b53bafed16584afa1703b
diff --git a/frontend/apps/reader/readerui.lua b/frontend/apps/reader/readerui.lua
index d30806e55..46c2fa97d 100644
--- a/frontend/apps/reader/readerui.lua
+++ b/frontend/apps/reader/readerui.lua
@@ -52,6 +52,8 @@ it works using data gathered from a document interface
 ]]--
 
 local ReaderUI = InputContainer:new{
+    name = "ReaderUI",
+
     key_events = {
         Close = { { "Home" },
             doc = "close document", event = "Close" },
@@ -74,6 +76,7 @@ local ReaderUI = InputContainer:new{
 
 function ReaderUI:registerModule(name, ui_module, always_active)
     if name then self[name] = ui_module end
+    ui_module.name = "reader" .. name
     table.insert(always_active and self.active_widgets or self, ui_module)
 end
 
diff --git a/frontend/dbg.lua b/frontend/dbg.lua
index 4fec08f63..2b1836742 100644
--- a/frontend/dbg.lua
+++ b/frontend/dbg.lua
@@ -3,6 +3,7 @@ local isAndroid, android = pcall(require, "android")
 
 local Dbg = {
     is_on = nil,
+    is_verbose = nil,
     ev_log = nil,
 }
 
@@ -59,6 +60,16 @@ function Dbg:turnOff()
     end
 end
 
+function Dbg:setVerbose(verbose)
+    self.is_verbose = verbose
+end
+
+function Dbg:v(...)
+    if self.is_verbose then
+        LvDEBUG(math.huge, ...)
+    end
+end
+
 function Dbg:logEv(ev)
     local log = ev.type.."|"..ev.code.."|"
                 ..ev.value.."|"..ev.time.sec.."|"..ev.time.usec.."\n"
diff --git a/frontend/ui/uimanager.lua b/frontend/ui/uimanager.lua
index 5f54bbc57..3b0aa4228 100644
--- a/frontend/ui/uimanager.lua
+++ b/frontend/ui/uimanager.lua
@@ -152,6 +152,12 @@ end
 -- modal widget should be always on the top
 -- for refreshtype & refreshregion see description of setDirty()
 function UIManager:show(widget, refreshtype, refreshregion, x, y)
+    if not widget then
+        dbg("widget not exist to be closed")
+        return
+    end
+    dbg("show widget", widget.id or widget.name or "unknown")
+
     self._running = true
     local window = {x = x or 0, y = y or 0, widget = widget}
     -- put this window on top of the toppest non-modal window
@@ -182,7 +188,7 @@ function UIManager:close(widget, refreshtype, refreshregion)
         dbg("widget not exist to be closed")
         return
     end
-    dbg("close widget", widget.id)
+    dbg("close widget", widget.id or widget.name)
     local dirty = false
     -- first send close event to widget
     widget:handleEvent(Event:new("CloseWidget"))
@@ -328,7 +334,7 @@ dbg:guard(UIManager, 'setDirty',
             if self._window_stack[i].widget == widget then found = true end
         end
         if not found then
-            dbg("INFO: invalid widget for setDirty()", debug.traceback())
+            dbg:v("INFO: invalid widget for setDirty()", debug.traceback())
         end
     end)
 
@@ -382,6 +388,7 @@ end
 
 -- transmit an event to an active widget
 function UIManager:sendEvent(event)
+    --dbg:v("send event", event)
     if #self._window_stack == 0 then return end
 
     local top_widget = self._window_stack[#self._window_stack]
@@ -395,22 +402,25 @@ function UIManager:sendEvent(event)
         end
     end
 
-    -- if the event is not consumed, active widgets (from top to bottom) can
+    -- if the event is not consumed, widgets (from top to bottom) can
     -- access it. NOTE: _window_stack can shrink on close event
     local checked_widgets = {top_widget}
     for i = #self._window_stack, 1, -1 do
         local widget = self._window_stack[i]
         if checked_widgets[widget] == nil then
-            if widget.widget.is_always_active then
-                checked_widgets[widget] = true
-                if widget.widget:handleEvent(event) then return end
-            end
+            -- active widgets has precedence to handle this event
+            -- Note: ReaderUI currently only has one active_widget: readerscreenshot
             if widget.widget.active_widgets then
                 checked_widgets[widget] = true
                 for _, active_widget in ipairs(widget.widget.active_widgets) do
                     if active_widget:handleEvent(event) then return end
                 end
             end
+            -- ordinary widgets will handle this event
+            -- Note: is_always_active widgets currently are vitualkeyboard and
+            -- readerconfig
+            checked_widgets[widget] = true
+            if widget.widget:handleEvent(event) then return end
         end
     end
 end
diff --git a/frontend/ui/widget/eventlistener.lua b/frontend/ui/widget/eventlistener.lua
index 88aaaeea7..9433a3d6c 100644
--- a/frontend/ui/widget/eventlistener.lua
+++ b/frontend/ui/widget/eventlistener.lua
@@ -6,6 +6,7 @@ will call a method "onEventName" for an event with name
 "EventName"
 --]]
 local EventListener = {}
+local DEBUG = require("dbg")
 
 function EventListener:new(new_o)
     local o = new_o or {}
@@ -17,6 +18,9 @@ end
 
 function EventListener:handleEvent(event)
     if self[event.handler] then
+        if self.id or self.name then
+            DEBUG:v(self.id or self.name, "handling event", event)
+        end
         return self[event.handler](self, unpack(event.args))
     end
 end
diff --git a/reader.lua b/reader.lua
index ffe5adb82..06044d639 100755
--- a/reader.lua
+++ b/reader.lua
@@ -48,6 +48,7 @@ local function showusage()
     print("Read all the books on your E-Ink reader")
     print("")
     print("-d               start in debug mode")
+    print("-v               debug in verbose mode")
     print("-p               enable Lua code profiling")
     print("-h               show this usage help")
     print("")
@@ -82,6 +83,8 @@ while argidx <= #ARGV do
         return showusage()
     elseif arg == "-d" then
         DEBUG:turnOn()
+    elseif arg == "-v" then
+        DEBUG:setVerbose(true)
     elseif arg == "-p" then
         Profiler = require("jit.p")
         Profiler.start("la")
diff --git a/spec/unit/dbg_spec.lua b/spec/unit/dbg_spec.lua
index 1e275a0e8..001a23e70 100644
--- a/spec/unit/dbg_spec.lua
+++ b/spec/unit/dbg_spec.lua
@@ -1,17 +1,26 @@
 describe("Dbg module", function()
-    local dbg
+    local dbg, dbg_on
     setup(function()
         package.path = "?.lua;common/?.lua;rocks/share/lua/5.1/?.lua;frontend/?.lua;" .. package.path
         dbg = require("dbg")
+        dbg_on = dbg.is_on
+    end)
+
+    after_each(function()
+        if dbg_on then
+            dbg:turnOn()
+        else
+            dbg:turnOff()
+        end
     end)
 
     it("setup mt.__call and guard after tunrnOn is called", function()
+        dbg:turnOff()
         local old_call = getmetatable(dbg).__call
         local old_guard = dbg.guard
         dbg:turnOn()
         assert.is_not.same(old_call, getmetatable(dbg).__call)
         assert.is_not.same(old_guard, dbg.guard)
-        dbg:turnOff()
     end)
 
     it("should call pre_gard callback", function()
@@ -27,7 +36,6 @@ describe("Dbg module", function()
         dbg:guard(foo, 'bar', function() called = true end)
         foo:bar()
         assert.is.truthy(called)
-        dbg:turnOff()
     end)
 
     it("should call post_gard callback", function()
@@ -43,7 +51,6 @@ describe("Dbg module", function()
         dbg:guard(foo, 'bar', nil, function() called = true end)
         foo:bar()
         assert.is.truthy(called)
-        dbg:turnOff()
     end)
 
     it("should return all values returned by the guarded function", function()
@@ -64,6 +71,5 @@ describe("Dbg module", function()
         assert.is.falsy(called)
         re = {foo:bar()}
         assert.is.same(re, {1, 2, 3})
-        dbg:turnOff()
     end)
 end)
diff --git a/spec/unit/device_spec.lua b/spec/unit/device_spec.lua
index fb2280606..724bb7b93 100644
--- a/spec/unit/device_spec.lua
+++ b/spec/unit/device_spec.lua
@@ -187,6 +187,7 @@ describe("device module", function()
             Device.isKobo:revert()
             NickelConf.frontLightLevel.get:revert()
             NickelConf.frontLightState.get:revert()
+            readerui.onFlushSettings:revert()
             UIManager._startAutoSuspend = nil
             UIManager._stopAutoSuspend = nil
             UIManager._resetAutoSuspendTimer = saved_noop
diff --git a/spec/unit/readerlink_spec.lua b/spec/unit/readerlink_spec.lua
index d1fcc8a5d..18526401a 100644
--- a/spec/unit/readerlink_spec.lua
+++ b/spec/unit/readerlink_spec.lua
@@ -41,7 +41,10 @@ describe("ReaderLink module", function()
         readerui.paging:onGotoPage(1)
         readerui.link:onTap(nil, {pos = {x = 250, y = 534}})
         UIManager:run()
-        assert.is.same(21, readerui.paging.current_page)
+        -- its really hard to get the exact page number in scroll mode
+        -- page positions may have unexpected impact on page number
+        assert.truthy(readerui.paging.current_page == 21
+            or readerui.paging.current_page == 20)
     end)
 
     it("should be able to go back after link jump in epub", function()
@@ -78,7 +81,8 @@ describe("ReaderLink module", function()
         readerui.paging:onGotoPage(1)
         readerui.link:onTap(nil, {pos = {x = 250, y = 534}})
         UIManager:run()
-        assert.is.same(21, readerui.paging.current_page)
+        assert.truthy(readerui.paging.current_page == 21
+            or readerui.paging.current_page == 20)
         readerui.link:onGoBackLink()
         assert.is.same(1, readerui.paging.current_page)
     end)
diff --git a/spec/unit/readerpaging_spec.lua b/spec/unit/readerpaging_spec.lua
index 006ed9fb4..fb69a0aa8 100644
--- a/spec/unit/readerpaging_spec.lua
+++ b/spec/unit/readerpaging_spec.lua
@@ -1,22 +1,27 @@
 describe("Readerpaging module", function()
     local sample_pdf = "spec/front/unit/data/sample.pdf"
-    local readerui
+    local readerui, UIManager, Event
     local paging
 
-    setup(function() require("commonrequire") end)
+    setup(function()
+        require("commonrequire")
+        UIManager = require("ui/uimanager")
+        Event = require("ui/event")
+    end)
 
     describe("Page mode", function()
-        local Event
-
         setup(function()
-            Event = require("ui/event")
             readerui = require("apps/reader/readerui"):new{
                 document = require("document/documentregistry"):openDocument(sample_pdf),
             }
             paging = readerui.paging
         end)
 
-        it("should emit EndOfBook event at the end in page mode", function()
+        it("should emit EndOfBook event at the end", function()
+            UIManager:quit()
+            UIManager:show(readerui)
+            UIManager:scheduleIn(1, function() UIManager:close(readerui) end)
+            UIManager:run()
             readerui:handleEvent(Event:new("SetScrollMode", false))
             readerui.zooming:setZoomMode("pageheight")
             paging:onGotoPage(readerui.document:getPageCount())
@@ -27,19 +32,7 @@ describe("Readerpaging module", function()
             paging:onPagingRel(1)
             assert.is.truthy(called)
             readerui.onEndOfBook = nil
-        end)
-
-        it("should emit EndOfBook event at the end in scroll mode", function()
-            readerui:handleEvent(Event:new("SetScrollMode", true))
-            paging:onGotoPage(readerui.document:getPageCount())
-            readerui.zooming:setZoomMode("pageheight")
-            local called = false
-            readerui.onEndOfBook = function()
-                called = true
-            end
-            paging:onPagingRel(1)
-            assert.is.truthy(called)
-            readerui.onEndOfBook = nil
+            UIManager:quit()
         end)
     end)
 
@@ -57,16 +50,23 @@ describe("Readerpaging module", function()
         end)
 
         it("should emit EndOfBook event at the end", function()
+            UIManager:quit()
+            UIManager:show(readerui)
+            UIManager:scheduleIn(1, function() UIManager:close(readerui) end)
+            UIManager:run()
+            paging.page_positions = {}
+            readerui:handleEvent(Event:new("SetScrollMode", true))
             paging:onGotoPage(readerui.document:getPageCount())
             readerui.zooming:setZoomMode("pageheight")
-            readerui.view:onSetScrollMode(true)
             local called = false
             readerui.onEndOfBook = function()
                 called = true
             end
             paging:onPagingRel(1)
+            paging:onPagingRel(1)
             assert.is.truthy(called)
             readerui.onEndOfBook = nil
+            UIManager:quit()
         end)
     end)
 end)
diff --git a/spec/unit/readerview_spec.lua b/spec/unit/readerview_spec.lua
index e22a99e5e..dae5cbeab 100644
--- a/spec/unit/readerview_spec.lua
+++ b/spec/unit/readerview_spec.lua
@@ -51,6 +51,7 @@ describe("Readerview module", function()
             document = DocumentRegistry:openDocument(sample_pdf),
         }
         readerui:handleEvent(Event:new("SetScrollMode", false))
+        readerui.zooming:setZoomMode("page")
         local view = readerui.view
         local ctx = view:getViewContext()
         local zoom = ctx[1].zoom
@@ -98,6 +99,7 @@ describe("Readerview module", function()
             document = DocumentRegistry:openDocument(sample_pdf),
         }
         readerui:handleEvent(Event:new("SetScrollMode", true))
+        readerui.zooming:setZoomMode("page")
         local view = readerui.view
         local ctx = view:getViewContext()
         local zoom = ctx[1].zoom