[chore] Some Wi-Fi tweaks (#4564)

* On Kobo, kill WiFi on startup if we detect an inconsistent state...

Untested, not terribly pretty.

The other solution is to slow down the Wi-Fi meny by doing the same
check for the "Wi-Fi connection" checkbox as in the later wifi_status
one...

* Don't enable auto_restore_wifi by default

It's liable to silently murder batteries for no good reason, given that
we prompt to enable WiFi by default when needed, and we otherwise have
no actual need to keep WiFi on in the background.

re #2215 (in particular, this directly contradicts @houqp in
https://github.com/koreader/koreader/pull/2215#discussion_r74696133 ;)).

frontend/device/generic/device.lua

@@ -154,7 +154,7 @@ function Device:onPowerEvent(ev)
                 local UIManager = require("ui/uimanager")
                 UIManager:unschedule(self.suspend)
                 local network_manager = require("ui/network/manager")
-                if network_manager.wifi_was_on and G_reader_settings:nilOrTrue("auto_restore_wifi") then
+                if network_manager.wifi_was_on and G_reader_settings:isTrue("auto_restore_wifi") then
                     network_manager:restoreWifiAsync()
                 end
                 self:resume()

frontend/ui/network/manager.lua

@@ -5,6 +5,7 @@ local InfoMessage = require("ui/widget/infomessage")
 local LuaSettings = require("luasettings")
 local UIManager = require("ui/uimanager")
 local ffiutil = require("ffi/util")
+local logger = require("logger")
 local _ = require("gettext")
 local T = ffiutil.template
 
@@ -15,8 +16,15 @@ function NetworkMgr:readNWSettings()
 end
 
 function NetworkMgr:init()
+    -- On Kobo, kill WiFi if NetworkMgr:isWifiOn() and NOT NetworkMgr:isConnected()
+    -- (i.e., if the launcher left the WiFi in an inconsistent state: modules loaded, but no route to gateway).
+    if Device:isKobo() and self:isWifiOn() and not self:isConnected() then
+        logger.info("Kobo WiFi: Left in an inconsistent state by launcher!")
+        self:turnOffWifi()
+    end
+
     self.wifi_was_on = G_reader_settings:isTrue("wifi_was_on")
-    if self.wifi_was_on and G_reader_settings:nilOrTrue("auto_restore_wifi") then
+    if self.wifi_was_on and G_reader_settings:isTrue("auto_restore_wifi") then
         self:restoreWifiAsync()
     end
 end
@@ -186,9 +194,9 @@ end
 function NetworkMgr:getRestoreMenuTable()
     return {
         text = _("Automatically restore Wi-Fi connection after resume"),
-        checked_func = function() return G_reader_settings:nilOrTrue("auto_restore_wifi") end,
+        checked_func = function() return G_reader_settings:isTrue("auto_restore_wifi") end,
         enabled_func = function() return Device:isKobo() or Device:isCervantes() end,
-        callback = function() G_reader_settings:flipNilOrTrue("auto_restore_wifi") end,
+        callback = function() G_reader_settings:flipNilOrFalse("auto_restore_wifi") end,
     }
 end
 

spec/unit/network_manager_spec.lua

@@ -6,6 +6,7 @@ describe("network_manager module", function()
     local release_ip_called
 
     local function clearState()
+        G_reader_settings:saveSetting("auto_restore_wifi", true)
         turn_on_wifi_called = 0
         turn_off_wifi_called = 0
         obtain_ip_called = 0