standarize mtime when git checkout

["Rick Liu" <rickliu@broadcom.com>]

Hi,

Currently when doing "git checkout" (either for a branch or a tag),
if the file doesn't exist before,
the file will be created using current datetime.

This causes problem while trying to tar the git repository source files (excluding .git folder).
The tar binary can be different 
even all of file contents are the same (eg. from the same GIT commit)
because the mtime for the files might be different due to different "git checkout" time.

eg:
User A checkout the commit at time A and then tarball the folder.
User B checkout the same commit as time B and then tarball the folder.
The result tarball are binary different 
even though all of tarball contents are the same 
except the mtime for each file.


Can we use GIT's commit time as the mtime for all of files/folders when we do "git checkout"?


Rick