when the file's apparent size is not a multiple of its block size.
* src/copy.c (copy_reg): Don't write a NUL before calling ftruncate.
For some file sizes, writing that single byte would unnecessarily
waste a few file blocks. That write may have been necessary in the
early days of Linux, but now, removing it should be safe.
Based on a patch by Alan Curry: <http://bugs.debian.org/370792>
* tests/cp/sparse: New test for the above.
* tests/cp/Makefile.am (TESTS): Add sparse.
* tests/sparse-file: New file, essence factored out of...
* tests/du/8gb: ... here. Use the new script.
