Fixed #8203 -- Fixed temporary file deleation on Windows and a couple of edge

cases on Unix-like systems. Patch from snaury. Testing and verification on
Windows, Mac and Linux from cgrady and ramikassab.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@8493 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 49 insertions, 21 deletions

diff --git a/django/core/files/move.py b/django/core/files/move.py
index 5ae776c3dd..58a0ab125d 100644
--- a/django/core/files/move.py
+++ b/django/core/files/move.py
@@ -8,13 +8,31 @@ Move a file in the safest way possible::
 import os
 from django.core.files import locks
 
-__all__ = ['file_move_safe']
-
 try:
-    import shutil
-    file_move = shutil.move
+    from shutil import copystat
 except ImportError:
-    file_move = os.rename
+    def copystat(src, dst):
+        """Copy all stat info (mode bits, atime and mtime) from src to dst"""
+        st = os.stat(src)
+        mode = stat.S_IMODE(st.st_mode)
+        if hasattr(os, 'utime'):
+            os.utime(dst, (st.st_atime, st.st_mtime))
+        if hasattr(os, 'chmod'):
+            os.chmod(dst, mode)
+
+__all__ = ['file_move_safe']
+
+def _samefile(src, dst):
+    # Macintosh, Unix.
+    if hasattr(os.path,'samefile'):
+        try:
+            return os.path.samefile(src, dst)
+        except OSError:
+            return False
+
+    # All other platforms: check for same pathname.
+    return (os.path.normcase(os.path.abspath(src)) ==
+            os.path.normcase(os.path.abspath(dst)))
 
 def file_move_safe(old_file_name, new_file_name, chunk_size = 1024*64, allow_overwrite=False):
     """
@@ -30,31 +48,41 @@ def file_move_safe(old_file_name, new_file_name, chunk_size = 1024*64, allow_ove
     """
 
     # There's no reason to move if we don't have to.
-    if old_file_name == new_file_name:
+    if _samefile(old_file_name, new_file_name):
         return
 
-    if not allow_overwrite and os.path.exists(new_file_name):
-        raise IOError("Cannot overwrite existing file '%s'." % new_file_name)
-
     try:
-        file_move(old_file_name, new_file_name)
+        os.rename(old_file_name, new_file_name)
         return
     except OSError:
         # This will happen with os.rename if moving to another filesystem
+        # or when moving opened files on certain operating systems
         pass
 
-    # If the built-in didn't work, do it the hard way.
-    fd = os.open(new_file_name, os.O_WRONLY | os.O_CREAT | os.O_EXCL | getattr(os, 'O_BINARY', 0))
+    # first open the old file, so that it won't go away
+    old_file = open(old_file_name, 'rb')
     try:
-        locks.lock(fd, locks.LOCK_EX)
-        old_file = open(old_file_name, 'rb')
-        current_chunk = None
-        while current_chunk != '':
-            current_chunk = old_file.read(chunk_size)
-            os.write(fd, current_chunk)
+        # now open the new file, not forgetting allow_overwrite
+        fd = os.open(new_file_name, os.O_WRONLY | os.O_CREAT | getattr(os, 'O_BINARY', 0) |
+                                    (not allow_overwrite and os.O_EXCL or 0))
+        try:
+            locks.lock(fd, locks.LOCK_EX)
+            current_chunk = None
+            while current_chunk != '':
+                current_chunk = old_file.read(chunk_size)
+                os.write(fd, current_chunk)
+        finally:
+            locks.unlock(fd)
+            os.close(fd)
     finally:
-        locks.unlock(fd)
-        os.close(fd)
         old_file.close()
+    copystat(old_file_name, new_file_name)
 
-    os.remove(old_file_name)
+    try:
+        os.remove(old_file_name)
+    except OSError, e:
+        # Certain operating systems (Cygwin and Windows)
+        # fail when deleting opened files, ignore it
+        if getattr(e, 'winerror', 0) != 32:
+            # FIXME: should we also ignore errno 13?
+            raise