Pygit2 truncates diff from Linux kernel commit bb8d8a6f54c1

[tohojo]

The diff output of commit bb8d8a6f54c1 in the Linux kernel is truncated by pygit2. Here's a minimal reproducer:

Assuming 'linux' contains a Linux kernel tree such as one that can be obtained by git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git:

import pygit2

r = pygit2.Repository("linux")
c = r.get('bb8d8a6f54c1')
print(c.parents[0].tree.diff_to_tree(c.tree).patch)

This ends with half a hunk:

@@ -431,6 +440,7 @@ static int compute_bitstructs(struct gfs2_rgrpd *rgd)
 }
 
 /**
+

The same hunk as output by git show bb8d8a6f54c1 (without a pager):

@@ -431,6 +440,7 @@ static int compute_bitstructs(struct gfs2_rgrpd *rgd)
 }
 
 /**
+
  * gfs2_ri_total - Total up the file system space, according to the rindex.
  *
  */

Note that when using 'less' as a pager, it shows this hunk as:

@@ -431,6 +440,7 @@ static int compute_bitstructs(struct gfs2_rgrpd *rgd)
 }
 
 /**
+^@
  * gfs2_ri_total - Total up the file system space, according to the rindex.
  *
  */

(note the ^@ escape). I suspect maybe there's a NULL byte in the middle of the hunk output for some reason, and that this causes the diff to be terminated prematurely in pygit2?