Test failures with GNU grep 2.23

[John Keeping <john@keeping.me.uk>]

It seems that binary file detection has changed in GNU grep 2.23 as a
result of commit 40ed879 (grep: fix bug with with invalid unibyte
sequence).

This causes a couple of test failures in t8005 and t9200 (the t9200 case
is less obvious so I'm only including t8005 here):

-- >8 --
$ ./t8005-blame-i18n.sh -v -i
[snip]
expecting success: 
        git blame --incremental file | \
                egrep "^(author|summary) " > actual &&
        test_cmp actual expected

--- actual      2016-02-07 16:14:55.372510307 +0000
+++ expected    2016-02-07 16:14:55.359510341 +0000
@@ -1 +1,6 @@
-Binary file (standard input) matches
+author �R�c ���Y
+summary �u���[���̃e�X�g�ł��B
+author �R�c ���Y
+summary �u���[���̃e�X�g�ł��B
+author �R�c ���Y
+summary �u���[���̃e�X�g�ł��B
not ok 2 - blame respects i18n.commitencoding
#
#               git blame --incremental file | \
#                       egrep "^(author|summary) " > actual &&
#               test_cmp actual expected
#
-- 8< --

The following patch fixes the tests for me, but I wonder if "-a" is
supported on all target platforms (it's not in POSIX, which specifies
that the "input files shall be text files") or whether we should do
something more comprehensive to provide sane_{e,f,}grep which guarantee
to treat input as text.

I also tried setting POSIXLY_CORRECT but that doesn't affect the
text/binary decision.

-- >8 --
diff --git a/t/t8005-blame-i18n.sh b/t/t8005-blame-i18n.sh
index 847d098..3b6e697 100755
--- a/t/t8005-blame-i18n.sh
+++ b/t/t8005-blame-i18n.sh
@@ -36,7 +36,7 @@ EOF
 test_expect_success !MINGW \
 	'blame respects i18n.commitencoding' '
 	git blame --incremental file | \
-		egrep "^(author|summary) " > actual &&
+		egrep -a "^(author|summary) " > actual &&
 	test_cmp actual expected
 '
 
@@ -53,7 +53,7 @@ test_expect_success !MINGW \
 	'blame respects i18n.logoutputencoding' '
 	git config i18n.logoutputencoding eucJP &&
 	git blame --incremental file | \
-		egrep "^(author|summary) " > actual &&
+		egrep -a "^(author|summary) " > actual &&
 	test_cmp actual expected
 '
 
@@ -69,7 +69,7 @@ EOF
 test_expect_success !MINGW \
 	'blame respects --encoding=UTF-8' '
 	git blame --incremental --encoding=UTF-8 file | \
-		egrep "^(author|summary) " > actual &&
+		egrep -a "^(author|summary) " > actual &&
 	test_cmp actual expected
 '
 
@@ -85,7 +85,7 @@ EOF
 test_expect_success !MINGW \
 	'blame respects --encoding=none' '
 	git blame --incremental --encoding=none file | \
-		egrep "^(author|summary) " > actual &&
+		egrep -a "^(author|summary) " > actual &&
 	test_cmp actual expected
 '
 
diff --git a/t/t9200-git-cvsexportcommit.sh b/t/t9200-git-cvsexportcommit.sh
index 5cfb9cf..f05578a 100755
--- a/t/t9200-git-cvsexportcommit.sh
+++ b/t/t9200-git-cvsexportcommit.sh
@@ -35,7 +35,7 @@ exit 1
 
 check_entries () {
 	# $1 == directory, $2 == expected
-	grep '^/' "$1/CVS/Entries" | sort | cut -d/ -f2,3,5 >actual
+	grep -a '^/' "$1/CVS/Entries" | sort | cut -d/ -f2,3,5 >actual
 	if test -z "$2"
 	then
 		>expected