--autounmask-write: handle non-existent file

diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index 3daaf441c2c152d6b23ca846e5a5d0b19cbb0cdd..9f3c1ac710fd4ef1528dafce8abd229d4c641456 100644 (file)
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -5,6 +5,7 @@ from __future__ import print_function
 
 import codecs
 import difflib
+import errno
 import gc
 import logging
 import re
@@ -5672,6 +5673,18 @@ class depgraph(object):
                        no suitable file exists.
                        """
                        file_path = os.path.join(abs_user_config, file_name)
+
+                       try:
+                               os.lstat(file_path)
+                       except OSError as e:
+                               if e.errno == errno.ENOENT:
+                                       # The file doesn't exist, so we'll
+                                       # simply create it.
+                                       return file_path
+
+                               # Disk or file system trouble?
+                               return None
+
                        last_file_path = None
                        stack = [file_path]
                        while stack:
@@ -5759,6 +5772,7 @@ class depgraph(object):
                                        shlex_split(settings.get("CONFIG_PROTECT_MASK", "")))
 
                def write_changes(root, changes, file_to_write_to):
+                       file_contents = None
                        try:
                                file_contents = codecs.open(
                                        _unicode_encode(file_to_write_to,
@@ -5766,8 +5780,12 @@ class depgraph(object):
                                        mode='r', encoding=_encodings['content'],
                                        errors='replace').readlines()
                        except IOError as e:
-                               problems.append("!!! Failed to read '%s': %s\n" % (file_to_write_to, e))
-                       else:
+                               if e.errno == errno.ENOENT:
+                                       file_contents = []
+                               else:
+                                       problems.append("!!! Failed to read '%s': %s\n" % \
+                                               (file_to_write_to, e))
+                       if file_contents is not None:
                                file_contents.extend(changes)
                                if protect_obj[root].isprotected(file_to_write_to):
                                        file_to_write_to = new_protect_filename(file_to_write_to)