The strop module and test_strop.py believe replace() with a 0 count
means "replace everything". But the string module, string.replace()
amd test_string.py believe a 0 count means "replace nothing".
"Nothing" wins, strop loses.
Bugfix candidate.
diff --git a/Lib/test/test_strop.py b/Lib/test/test_strop.py
index 5770046..de7a795 100644
--- a/Lib/test/test_strop.py
+++ b/Lib/test/test_strop.py
@@ -77,7 +77,7 @@
test('replace', 'one!two!three!', 'one@two@three!', '!', '@', 2)
test('replace', 'one!two!three!', 'one@two@three@', '!', '@', 3)
test('replace', 'one!two!three!', 'one@two@three@', '!', '@', 4)
-test('replace', 'one!two!three!', 'one@two@three@', '!', '@', 0)
+test('replace', 'one!two!three!', 'one!two!three!', '!', '@', 0)
test('replace', 'one!two!three!', 'one@two@three@', '!', '@')
test('replace', 'one!two!three!', 'one!two!three!', 'x', '@')
test('replace', 'one!two!three!', 'one!two!three!', 'x', '@', 2)