romfs_pruner: delete hidden files, remove tabs

If a text editor creates hidden save files, those will get copied into
the ROMFS. This is now fixed by deleting hidden files.

Also, the there was some available potential by removing the leading
whitespace.

Tools/px_romfs_pruner.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 ############################################################################
 #
-#   Copyright (C) 2014-2015 PX4 Development Team. All rights reserved.
+#   Copyright (C) 2014-2016 PX4 Development Team. All rights reserved.
 
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -35,7 +35,12 @@
 
 """
 px_romfs_pruner.py:
-Delete all comments and newlines before ROMFS is converted to an image
+Try to keep size of ROMFS minimal.
+
+This script goes through the temporarily copied ROMFS data and deletes all
+comments, empty lines and leading whitespace.
+It also deletes hidden files such as auto-saved backups that a text editor
+might have left in the tree.
 
 @author: Julian Oes <julian@oes.ch>
 """
@@ -53,19 +58,21 @@ def main():
                         help="ROMFS scratch folder.")
     args = parser.parse_args()
 
-    #print("Pruning ROMFS files.")
-
-    # go through
+    # go through temp folder
     for (root, dirs, files) in os.walk(args.folder):
         for file in files:
+            file_path = os.path.join(root, file)
+
+            # delete hidden files
+            if file.startswith("."):
+                os.remove(file_path)
+                continue
+
             # only prune text files
             if ".zip" in file or ".bin" in file or ".swp" in file \
-                    or ".data" in file or ".DS_Store" in file \
-                    or file.startswith("."):
+                    or ".data" in file or ".DS_Store" in file:
                 continue
 
-            file_path = os.path.join(root, file)
-
             # read file line by line
             pruned_content = ""
             with open(file_path, "rU") as f:
@@ -77,7 +84,7 @@ def main():
                     else:
                         if not line.isspace() \
                                 and not line.strip().startswith("#"):
-                            pruned_content += line
+                            pruned_content += line.strip() + "\n"
             # overwrite old scratch file
             with open(file_path, "wb") as f:
                 pruned_content = re.sub("\r\n", "\n", pruned_content)