[PATCH v2] t4015: improve coverage of function context test

["René Scharfe" <l.s.r@web.de>]

Add a test that includes an actual function line in the test file to
check if context is expanded to include the whole function, and add an
ignored change before function context to check if that one stays hidden
while the originally ignored change within function context is shown.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: René Scharfe <l.s.r@web.de>
---
Changes:
* Keep existing test intact, add a new one instead.
* Use unique content for the part before the function context to make
  clear that it's independent.

 t/t4015-diff-whitespace.sh | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 65615e2fa9..88d3026894 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -2068,4 +2068,27 @@ test_expect_success 'combine --ignore-blank-lines with --function-context' '
 	test_cmp expect actual
 '

+test_expect_success 'combine --ignore-blank-lines with --function-context 2' '
+	test_write_lines    a b c "" function 1 2 3 4 5 "" 6 7 8 9 >a &&
+	test_write_lines "" a b c "" function 1 2 3 4 5    6 7 8   >b &&
+	test_must_fail git diff --no-index \
+		--ignore-blank-lines --function-context a b >actual.raw &&
+	sed -n "/@@/,\$p" <actual.raw >actual &&
+	cat <<-\EOF >expect &&
+	@@ -5,11 +6,9 @@ c
+	 function
+	 1
+	 2
+	 3
+	 4
+	 5
+	-
+	 6
+	 7
+	 8
+	-9
+	EOF
+	test_cmp expect actual
+'
+
 test_done
--
2.24.1