Fix find_in_path not including some file extension logic under win32. Windows shell resolves utility path by combining PATH, the utility name and a set of file extensions from PATHEXT.

#!/bin/sh

hg init
echo This is file a1 > a
hg add a
hg commit -m "commit #0" -d "1000000 0"
touch b
hg add b
rm b
hg commit -A -m"comment #1" -d "1000000 0"