bump crengine: fix max image height, handle <epub:switch> (#4390)

Includes:
- (Upstream) Fix dangerous compile warnings
- Fix max image height to prevent spurious page breaks
- Hide <epub:case> in <epub:switch>, show only <epub:default>

Adds a style tweak to show <epub:case> and hide <epub:default>
for the curious person.

frontend/ui/data/css_tweaks.lua

@@ -257,10 +257,23 @@ width: 100% !important;
             css = [[img { vertical-align: middle; }]],
         },
     },
-    -- No current need for Miscellaneous
-    -- {
-    --     title = _("Miscellaneous"),
-    -- },
+    {
+        title = _("Miscellaneous"),
+        {
+            id = "epub_switch_show_case";
+            title = _("Toggle alternative EPUB content"),
+            description = _([[
+The EPUB3 format allows a
+<epub:switch> <epub:case> <epub:default>
+construct to provide alternative content to engines that support optional features.
+KOReader currently falls back to hiding all <epub:case> content and shows the <epub:default> content (usually an image).
+This tweak toggles this behavior, and may show the <epub:case> content as plain text.]]),
+            css = [[
+switch > case    { display: inline; }
+switch > default { display: none; }
+            ]],
+        },
+    },
     -- No current need for workarounds
     -- {
     --     title = _("Workarounds"),

spec/unit/readerfooter_spec.lua

@@ -146,7 +146,7 @@ describe("Readerfooter module", function()
         local timeinfo = footer.textGeneratorMap.time()
         local page_count = readerui.document:getPageCount()
         -- stats has not been initialized here, so we get na TB and TC
-        assert.are.same('1 / '..page_count..' | '..timeinfo..' | => 1 | B:0% | R:0% | TB: na | TC: na',
+        assert.are.same('1 / '..page_count..' | '..timeinfo..' | => 0 | B:0% | R:0% | TB: na | TC: na',
                         footer.footer_text.text)
     end)
 

spec/unit/readerrolling_spec.lua

@@ -186,13 +186,13 @@ describe("Readerrolling module", function()
         it("should show pages for different word gap", function()
             readerui.document:setSpaceCondensing(100)
             readerui:handleEvent(Event:new("ChangeScreenMode", "portrait"))
-            assert.are.same(267, readerui.document:getPageCount())
+            assert.are.same(266, readerui.document:getPageCount())
             readerui.document:setSpaceCondensing(75)
             readerui:handleEvent(Event:new("ChangeScreenMode", "portrait"))
-            assert.are.same(262, readerui.document:getPageCount())
+            assert.are.same(261, readerui.document:getPageCount())
             readerui.document:setSpaceCondensing(50)
             readerui:handleEvent(Event:new("ChangeScreenMode", "portrait"))
-            assert.are.same(248, readerui.document:getPageCount())
+            assert.are.same(247, readerui.document:getPageCount())
         end)
     end)
 

spec/unit/readersearch_spec.lua

@@ -67,7 +67,7 @@ describe("Readersearch module", function()
         it("should find the last occurrence", function()
             -- local logger = require("logger")
             -- logger.info("nb of pages", doc:getPageCount())
-            -- 20181206: currently 267 pages
+            -- 20181208: currently 266 pages
             for i = 100, 180, 10 do
                 rolling:onGotoPage(i)
                 local words = search:searchFromEnd("Verona")