1 files changed, 57 insertions, 0 deletions
diff --git a/testsuite/tests/lib-stream/count_concat_bug.ml b/testsuite/tests/lib-stream/count_concat_bug.ml
new file mode 100644
index 000000000..97ec6bce2
--- /dev/null
+++ b/testsuite/tests/lib-stream/count_concat_bug.ml
@@ -0,0 +1,57 @@
+let is_empty s =
+  try Stream.empty s; true with Stream.Failure -> false
+
+let test_icons =
+  let s = Stream.of_string "ab" in
+  let s = Stream.icons 'c' s in
+  Testing.test (Stream.next s = 'c');
+  Testing.test (Stream.next s = 'a');
+  Testing.test (Stream.next s = 'b');
+  Testing.test (is_empty s);
+  ()
+
+let test_lcons =
+  let s = Stream.of_string "ab" in
+  let s = Stream.lcons (fun () -> 'c') s in
+  Testing.test (Stream.next s = 'c');
+  Testing.test (Stream.next s = 'a');
+  Testing.test (Stream.next s = 'b');
+  Testing.test (is_empty s);
+  ()
+
+let test_iapp =
+  let s = Stream.of_string "ab" in
+  let s = Stream.iapp (Stream.of_list ['c']) s in
+  Testing.test (Stream.next s = 'c');
+  Testing.test (Stream.next s = 'a');
+  Testing.test (Stream.next s = 'b');
+  Testing.test (is_empty s);
+  ()
+
+let test_lapp_right =
+  let s1 = Stream.of_list ['c'] in
+  let s2 = Stream.of_string "ab" in
+  let s = Stream.lapp (fun () -> s1) s2 in
+  Testing.test (Stream.next s = 'c');
+  Testing.test (Stream.next s = 'a');
+  Testing.test (Stream.next s = 'b');
+  Testing.test (is_empty s);
+  ()
+
+let test_lapp_left =
+  let s1 = Stream.of_string "bc" in
+  let s2 = Stream.of_list ['a'] in
+  Testing.test (Stream.next s1 = 'b');
+  let s = Stream.lapp (fun () -> s1) s2 in
+  Testing.test (Stream.next s = 'c');
+  Testing.test (Stream.next s = 'a');
+  Testing.test (is_empty s);
+  ()
+
+let test_slazy =
+  let s = Stream.of_string "ab" in
+  Testing.test (Stream.next s = 'a');
+  let s = Stream.slazy (fun () -> s) in
+  Testing.test (Stream.next s = 'b');
+  Testing.test (is_empty s);
+  ()