Minor Lua I/O cleanups (#8921)

Mostly making sure we always explicitly close io handles.

frontend/dbg.lua

@@ -80,11 +80,14 @@ function Dbg:turnOn()
     --- @note: On Linux, use CLOEXEC to avoid polluting the fd table of our child processes.
     ---        Otherwise, it can be problematic w/ wpa_supplicant & USBMS...
     ---        Note that this is entirely undocumented, but at least LuaJIT passes the mode as-is to fopen, so, we're good.
+    local open_flags = "w"
     if jit.os == "Linux" then
-        self.ev_log = io.open("ev.log", "we")
-    else
-        self.ev_log = io.open("ev.log", "w")
+        -- Oldest Kindle devices are too old to support O_CLOEXEC...
+        if os.getenv("KINDLE_LEGACY") ~= "yes" then
+            open_flags = "we"
+        end
     end
+    self.ev_log = io.open("ev.log", open_flags)
 end
 
 --- Turn off debug mode.
@@ -99,7 +102,7 @@ function Dbg:turnOff()
         return check
     end
     if self.ev_log then
-        io.close(self.ev_log)
+        self.ev_log:close()
         self.ev_log = nil
     end
 end

frontend/device/sysfs_light.lua

@@ -140,7 +140,7 @@ function SysfsLight:_write_value(file, value)
         return false
     end
     local ret, err_msg, err_code = f:write(value)
-    io.close(f)
+    f:close()
     if not ret then
         logger.err("Write error: ", err_msg, err_code)
         return false

frontend/gettext.lua

@@ -280,6 +280,7 @@ function GetText_mt.__index.changeLang(new_lang)
             end
         end
     end
+    po:close()
     GetText.current_lang = new_lang
 end
 

frontend/ui/wikipedia.lua

@@ -851,7 +851,8 @@ function Wikipedia:createEpub(epub_path, page, lang, with_images)
     --     </guide>
     local koreader_version = "KOReader"
     if lfs.attributes("git-rev", "mode") == "file" then
-        koreader_version = "KOReader "..io.open("git-rev", "r"):read("*line")
+        local Version = require("version")
+        koreader_version = "KOReader " .. Version:getCurrentRevision()
     end
     local content_opf_parts = {}
     -- head

platform/kindle/koreader.sh

@@ -226,6 +226,11 @@ fi
 # c.f., https://stackoverflow.com/a/37939589
 version() { echo "$@" | awk -F. '{ printf("%d%03d%03d\n", $1,$2,$3); }'; }
 
+# Detect kernels w/ CLOEXEC support
+if [ "$(version "$(uname -r | sed -n -r 's/^([[:digit:]\.]*)(.*?)$/\1/p')")" -lt "$(version "2.6.23")" ]; then
+    export KINDLE_LEGACY="yes"
+fi
+
 # There's no pillow if we stopped the framework, and it's only there on systems with upstart anyway
 if [ "${STOP_FRAMEWORK}" = "no" ] && [ "${INIT_TYPE}" = "upstart" ]; then
     # NOTE: If we were launched from KUAL, don't even try to deal with KPVBooklet-specific workarounds

plugins/exporter.koplugin/clip.lua

@@ -85,6 +85,7 @@ function MyClipping:parseMyClippings()
             end
             index = index + 1
         end
+        file:close()
     end
 
     return clippings

plugins/japanese.koplugin/deinflector.lua

@@ -58,6 +58,7 @@ local function parsePluginJson(filename)
     local file, err = io.open(jsonPath, "r")
     if file then
         local contents = file:read("*all")
+        file:close()
         local ok, parsed = pcall(JSON.decode, contents)
         if ok then
             return parsed

plugins/statistics.koplugin/main.lua

@@ -454,6 +454,7 @@ function ReaderStatistics:partialMd5(file)
             break
         end
     end
+    file_handle:close()
     return update()
 end
 

plugins/terminal.koplugin/main.lua

@@ -245,7 +245,7 @@ function Terminal:killShell(ask)
         return -1
     end
 
-    local pid = tonumber(pid_file:read("*a"))
+    local pid = pid_file:read("*n")
     pid_file:close()
 
     if ask then