1 files changed, 24 insertions, 0 deletions
diff --git a/test/std/input.output/string.streams/stringbuf/stringbuf.virtuals/seekoff.pass.cpp b/test/std/input.output/string.streams/stringbuf/stringbuf.virtuals/seekoff.pass.cpp
index 6d20db131..8ec69cb24 100644
--- a/test/std/input.output/string.streams/stringbuf/stringbuf.virtuals/seekoff.pass.cpp
+++ b/test/std/input.output/string.streams/stringbuf/stringbuf.virtuals/seekoff.pass.cpp
@@ -21,6 +21,30 @@
 int main()
 {
     {
+        std::stringbuf sb(std::ios_base::in);
+        assert(sb.pubseekoff(3, std::ios_base::beg, std::ios_base::out) == -1);
+        assert(sb.pubseekoff(3, std::ios_base::cur, std::ios_base::out) == -1);
+        assert(sb.pubseekoff(-3, std::ios_base::end, std::ios_base::out) == -1);
+        assert(sb.pubseekoff(3, std::ios_base::beg, std::ios_base::in | std::ios_base::out) == -1);
+        assert(sb.pubseekoff(3, std::ios_base::cur, std::ios_base::in | std::ios_base::out) == -1);
+        assert(sb.pubseekoff(-3, std::ios_base::end, std::ios_base::in | std::ios_base::out) == -1);
+        assert(sb.pubseekoff(0, std::ios_base::beg, std::ios_base::in) == 0);
+        assert(sb.pubseekoff(0, std::ios_base::cur, std::ios_base::in) == 0);
+        assert(sb.pubseekoff(0, std::ios_base::end, std::ios_base::in) == 0);
+    }
+    {
+        std::stringbuf sb(std::ios_base::out);
+        assert(sb.pubseekoff(3, std::ios_base::beg, std::ios_base::in) == -1);
+        assert(sb.pubseekoff(3, std::ios_base::cur, std::ios_base::in) == -1);
+        assert(sb.pubseekoff(-3, std::ios_base::end, std::ios_base::in) == -1);
+        assert(sb.pubseekoff(3, std::ios_base::beg, std::ios_base::in | std::ios_base::out) == -1);
+        assert(sb.pubseekoff(3, std::ios_base::cur, std::ios_base::in | std::ios_base::out) == -1);
+        assert(sb.pubseekoff(-3, std::ios_base::end, std::ios_base::in | std::ios_base::out) == -1);
+        assert(sb.pubseekoff(0, std::ios_base::beg, std::ios_base::out) == 0);
+        assert(sb.pubseekoff(0, std::ios_base::cur, std::ios_base::out) == 0);
+        assert(sb.pubseekoff(0, std::ios_base::end, std::ios_base::out) == 0);
+    }
+    {
         std::stringbuf sb("0123456789", std::ios_base::in);
         assert(sb.pubseekoff(3, std::ios_base::beg, std::ios_base::out) == -1);
         assert(sb.pubseekoff(3, std::ios_base::cur, std::ios_base::out) == -1);