pocketbook: detect if launcher script has changed

And a complete restart from the parent launcher is needed.

frontend/device/pocketbook/device.lua

@@ -413,6 +413,12 @@ function PocketBook:getDefaultCoverPath()
     return "/mnt/ext1/system/logo/offlogo/cover.bmp"
 end
 
+function PocketBook:isStartupScriptUpToDate()
+    local md5 = require("ffi/MD5")
+    -- Compare the hash of the *active* script to the *potential* one.
+    return md5.sumFile("/tmp/koreader.app") == md5.sumFile(os.getenv("KOREADER_DIR") .. "/koreader.app")
+end
+
 function PocketBook:UIManagerReady(uimgr)
     UIManager = uimgr
 end

platform/pocketbook/koreader.app

@@ -1,9 +1,19 @@
 #!/bin/sh
+
+# Relocalize ourselves to /tmp: this is used by KOReader to detect if the
+# original script has changed after an update (requiring a complete restart
+# from the parent launcher).
+if [ "$(dirname "${0}")" != '/tmp' ]; then
+    cp -pf "${0}" '/tmp/koreader.app'
+    chmod 777 '/tmp/koreader.app'
+    exec '/tmp/koreader.app' "$@"
+fi
+
 export LC_ALL="en_US.UTF-8"
 
 UNPACK_DIR='/mnt/ext1'
 # working directory of koreader
-KOREADER_DIR="${UNPACK_DIR}/applications/koreader"
+export KOREADER_DIR="${UNPACK_DIR}/applications/koreader"
 
 # load our own shared libraries if possible, solely because we don't control InkView, and we'd rather not it have load duplicate system libs...
 # (We handle this via DT_RPATH for our own stuff).