Explorer of Windows Vista and Windows 7 has the following bug:

When copying trees, it *removes* all spaces from the beginning
of file and directory names.

Tested on Vista 32bit, Vista 64bit and Windows 7 64bit.

This bug is *not* present in explorer.exe of Windows XP.

Note that on Windows Vista and Windows 7 (and of course Windows XP)
it is possible to create file and directory names beginning with
spaces using for example the rename command of cmd.exe:

rename a.txt " a.txt"

File- and directory names beginning with spaces are valid names
both for the OS and the file systems NTFS and FAT32.


Affected well known repository:

The python trunk repo for example contains the two files (names
given in double quotes):

"  separator ---.i"
"separator ---.i"

in ".hg/store/data/_mac/_i_d_e scripts".

If you try to copy that repo using explorer of Vista (or
Windows 7) you will get a warning box telling you that
it cannot copy the file "separator ---.i" to the destination
folder because that folder already contains a file with
that name (see attached copy-error.png).
No matter what the user chooses: the copied repo is broken
(fails on hg verify).