parsers: use correct type for file offset
Now using Py_ssize_t instead of long to denote offset in file whose length is
already measured using Py_ssize_t. Length and offset are now consistent. Based
on warning from Microsoft Visual C++ 2008.
#require symlink
http://mercurial.selenic.com/bts/issue1438
$ hg init
$ ln -s foo link
$ hg add link
$ hg ci -mbad link
$ hg rm link
$ hg ci -mok
$ hg diff -g -r 0:1 > bad.patch
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg import --no-commit bad.patch
applying bad.patch
$ hg status
R link
? bad.patch