diff --whitespace=warn/error: obey blank-at-eof

The "diff --check" code used to conflate trailing-space whitespace error
class with this, but now we have a proper separate error class, we should
check it under blank-at-eof, not trailing-space.

The whitespace error is not about _having_ blank lines at end, but about
adding _new_ blank lines.  To keep the message consistent with what is
given by "git apply", call whitespace_error_string() to generate it,
instead of using a hardcoded custom message.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index b1cbd36..a5d4461 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -335,10 +335,10 @@ test_expect_success 'line numbers in --check output are correct' '
 
 '
 
-test_expect_success 'checkdiff detects trailing blank lines' '
+test_expect_success 'checkdiff detects new trailing blank lines (1)' '
 	echo "foo();" >x &&
 	echo "" >>x &&
-	git diff --check | grep "ends with blank"
+	git diff --check | grep "new blank line"
 '
 
 test_expect_success 'checkdiff allows new blank lines' '