git: update to v2.20.0

Update to git version v2.20.0. Required changes follow upstream commits:

* 00436bf1b1c2a8fe6cf5d2c2457d419d683042f4
  (archive: initialize archivers earlier)

* 611e42a5980a3a9f8bb3b1b49c1abde63c7a191e
  (xdiff: provide a separate emit callback for hunks)

Signed-off-by: Christian Hesse <mail@eworm.de>

Makefile

@@ -14,7 +14,7 @@ htmldir = $(docdir)
 pdfdir = $(docdir)
 mandir = $(prefix)/share/man
 SHA1_HEADER = <openssl/sha.h>
-GIT_VER = 2.19.1
+GIT_VER = 2.20.0
 GIT_URL = https://www.kernel.org/pub/software/scm/git/git-$(GIT_VER).tar.xz
 INSTALL = install
 COPYTREE = cp -r

git

@@ -1 +1 @@
-Subproject commit cae598d9980661a978e2df4fb338518f7bf09572
+Subproject commit 5d826e972970a784bd7a7bdf587512510097b8c7

shared.c

@@ -325,7 +325,7 @@ int cgit_diff_files(const struct object_id *old_oid,
 		diff_params.flags |= XDF_IGNORE_WHITESPACE;
 	emit_params.ctxlen = context > 0 ? context : 3;
 	emit_params.flags = XDL_EMIT_FUNCNAMES;
-	emit_cb.outf = filediff_cb;
+	emit_cb.out_line = filediff_cb;
 	emit_cb.priv = fn;
 	xdl_diff(&file1, &file2, &diff_params, &emit_params, &emit_cb);
 	if (file1.size)

ui-snapshot.c

@@ -156,6 +156,7 @@ static int make_snapshot(const struct cgit_snapshot_format *format,
 	ctx.page.mimetype = xstrdup(format->mimetype);
 	ctx.page.filename = xstrdup(filename);
 	cgit_print_http_headers();
+	init_archivers();
 	format->write_func(hex, prefix);
 	return 0;
 }