Reader: do not apply font size out of range (#10295)

frontend/apps/reader/modules/readercoptlistener.lua

@@ -69,6 +69,9 @@ function ReaderCoptListener:onReadSettings(config)
 end
 
 function ReaderCoptListener:onConfigChange(option_name, option_value)
+    -- font_size is historically and sadly shared by both mupdf and cre reader modules,
+    -- but fortunately they can be distinguished by their different ranges
+    if option_name == "font_size" and option_value < 5 then return end
     self.document.configurable[option_name] = option_value
     self.ui:handleEvent(Event:new("StartActivityIndicator"))
     return true

frontend/apps/reader/modules/readerkoptlistener.lua

@@ -72,6 +72,9 @@ function ReaderKoptListener:onDocLangUpdate(lang)
 end
 
 function ReaderKoptListener:onConfigChange(option_name, option_value)
+    -- font_size is historically and sadly shared by both mupdf and cre reader modules,
+    -- but fortunately they can be distinguished by their different ranges
+    if option_name == "font_size" and option_value > 5 then return end
     self.document.configurable[option_name] = option_value
     self.ui:handleEvent(Event:new("StartActivityIndicator"))
     UIManager:setDirty("all", "partial")

frontend/apps/reader/modules/readerview.lua

@@ -1023,8 +1023,10 @@ function ReaderView:onSWDitheringUpdate(toggle)
 end
 
 function ReaderView:onFontSizeUpdate(font_size)
-    self.ui:handleEvent(Event:new("ReZoom", font_size))
-    Notification:notify(T(_("Font zoom set to: %1."), font_size))
+    if self.ui.paging then
+        self.ui:handleEvent(Event:new("ReZoom", font_size))
+        Notification:notify(T(_("Font zoom set to: %1."), font_size))
+    end
 end
 
 function ReaderView:onDefectSizeUpdate()

frontend/ui/data/creoptions.lua

@@ -437,7 +437,7 @@ Note that your selected font size is not affected by this setting.]]),
                 item_text = not Device:isTouchDevice() and {_("decrease"), _("increase")} or nil,
                 more_options = true,
                 more_options_param = {
-                    value_min = 7,
+                    value_min = 12,
                     value_max = 255,
                     value_step = 0.5,
                     precision = "%.1f",