commit 2af6017be9d15b5f6b5a4a394b51a22f8d2c3c54
Author: Felix Schwarz <felix.schwarz@oss.schwarz.eu>
Date:   Fri Jan 1 23:34:44 2021 +0100

    test_metadata: add workaround for changed PDF date string in cairo 1.17.4

diff --git a/cairocffi/test_cairo.py b/cairocffi/test_cairo.py
index 89e6bc4..a7c0abc 100644
--- a/cairocffi/test_cairo.py
+++ b/cairocffi/test_cairo.py
@@ -255,7 +255,17 @@ def test_metadata():
     assert b'/Creator (creator)' in pdf_bytes
     assert b'/Author (author)' in pdf_bytes
     assert b'/Keywords (keywords)' in pdf_bytes
-    assert b"/CreationDate (20130721234600+01'00)" in pdf_bytes
+    # According to PDF 32000-1:2008, section 7.9.4 ("Dates") PDF date strings
+    # do not end with a apostrophe even though that format was described in
+    # the "PDF reference, Sixth Edition".
+    #   See also: https://stackoverflow.com/q/41661477/138526
+    # cairo 1.17.4 contains a commit which adds the apostrophe unconditionally:
+    #   https://gitlab.freedesktop.org/cairo/cairo/-/issues/392#note_742384
+    if cairo_version() == 11704:
+        expected_date_string = b"/CreationDate (20130721234600+01'00')"
+    else:
+        expected_date_string = b"/CreationDate (20130721234600+01'00)"
+    assert expected_date_string in pdf_bytes
     assert b'/ModDate (20130721234600Z)' in pdf_bytes