Shutil.copyfile will open source with read share (#265)

Opens the source file used in shutil.copyfile with share_access="r" to
ensure that it can be copied even if something else already has it
opened with read access and grants further opens.

CHANGELOG.md

@@ -9,6 +9,7 @@
 * Added default timeout for disconnect operations for 60 seconds to ensure the process doesn't hang forever when closing a broken connection
 * `smbprotocol.connection.Connection.disconnect()` now waits (with a timeout) for the message processing threads to be stopped before returning.
 * Do not set the SMB SessionId and TreeId in the headers to `0xFFFFFFFF` for related compound requests
++ Ensures the source file for `shutil.copyfile` is opened with `share_access="r"` for better compatibility with files already opened by something else
 
 ## 1.12.0 - 2023-11-09
 

src/smbclient/shutil.py

@@ -130,13 +130,19 @@ def copyfile(src, dst, follow_symlinks=True, **kwargs):
         symlink_func = symlink
         src_open = open_file
         src_kwargs = kwargs
+
+        # Open the soruce with read file sharing to allow copying
+        # files already opened.
+        # https://github.com/jborean93/smbprotocol/issues/258
+        src_open_kwargs = kwargs.copy()
+        src_open_kwargs["share_access"] = "r"
     else:
         src_root = None
         islink_func = os.path.islink
         readlink_func = os.readlink
         symlink_func = os.symlink
         src_open = open
-        src_kwargs = {}
+        src_kwargs = src_open_kwargs = {}
 
     norm_dst = ntpath.normpath(dst)
     if is_remote_path(norm_dst):
@@ -178,7 +184,7 @@ def copyfile(src, dst, follow_symlinks=True, **kwargs):
         return dst
 
     # Finally we are copying across different roots so we just chunk the data using copyfileobj
-    with src_open(src, mode="rb", **src_kwargs) as src_fd, dst_open(dst, mode="wb", **dst_kwargs) as dst_fd:
+    with src_open(src, mode="rb", **src_open_kwargs) as src_fd, dst_open(dst, mode="wb", **dst_kwargs) as dst_fd:
         copyfileobj(src_fd, dst_fd, MAX_PAYLOAD_SIZE)
 
     return dst

tests/test_smbclient_shutil.py

@@ -4,6 +4,7 @@
 import ctypes
 import ntpath
 import os
+import os.path
 import re
 import shutil
 import stat
@@ -305,6 +306,23 @@ def test_copyfile_remote_to_local(smb_share, tmpdir):
         assert fd.read() == "content"
 
 
+def test_copyfile_remote_to_local_read_share(smb_share, tmpdir):
+    test_dir = tmpdir.mkdir("test")
+    src_filename = "%s\\source.txt" % smb_share
+    dst_filename = os.path.join(test_dir, "target.txt")
+
+    with open_file(src_filename, mode="w") as fd:
+        fd.write("content")
+
+    with open_file(src_filename, mode="r", share_access="r") as fd:
+        actual = copyfile(src_filename, dst_filename)
+
+    assert actual == dst_filename
+
+    with open(dst_filename) as fd:
+        assert fd.read() == "content"
+
+
 def test_copyfile_local_to_local(tmpdir):
     test_dir = tmpdir.mkdir("test")
     src_filename = "%s\\source.txt" % test_dir