appimage: get full path before changing to assets dir (#11552)

platform/appimage/AppRun

@@ -4,14 +4,22 @@ export LC_ALL="en_US.UTF-8"
 # working directory of koreader
 KOREADER_DIR="${0%/*}"
 
+if [ $# -eq 1 ] && [ -e "$(pwd)/${1}" ]; then
+    ARGS="$(pwd)/${1}"
+else
+    ARGS="${*}"
+fi
+
 # we're always starting from our working directory
 cd "${KOREADER_DIR}" || exit
 
 RETURN_VALUE=85
 
 while [ ${RETURN_VALUE} -eq 85 ]; do
-    ./reader.lua "$@"
+    ./reader.lua "${ARGS}"
     RETURN_VALUE=$?
+    # do not restart with saved arguments
+    ARGS="${HOME}"
 done
 
 exit ${RETURN_VALUE}