document with unit test rather odd embedded null handling

tools/qa/cppunit/test_stream.cxx

@@ -48,12 +48,14 @@ namespace
         void test_fastostring();
         void test_read_cstring();
         void test_read_pstring();
+        void test_readline();
 
         CPPUNIT_TEST_SUITE(Test);
         CPPUNIT_TEST(test_stdstream);
         CPPUNIT_TEST(test_fastostring);
         CPPUNIT_TEST(test_read_cstring);
         CPPUNIT_TEST(test_read_pstring);
+        CPPUNIT_TEST(test_readline);
         CPPUNIT_TEST_SUITE_END();
     };
 
@@ -210,6 +212,71 @@ namespace
         CPPUNIT_ASSERT(!aMemStream.eof());
     }
 
+    void Test::test_readline()
+    {
+        char foo[] = "foo\nbar\n\n";
+        SvMemoryStream aMemStream(RTL_CONSTASCII_STRINGPARAM(foo), STREAM_READ);
+
+        rtl::OString aFoo;
+        sal_Bool bRet;
+
+        bRet = aMemStream.ReadLine(aFoo);
+        CPPUNIT_ASSERT(bRet);
+        CPPUNIT_ASSERT(aFoo.equalsL(RTL_CONSTASCII_STRINGPARAM("foo")));
+        CPPUNIT_ASSERT(aMemStream.good());
+
+        bRet = aMemStream.ReadLine(aFoo);
+        CPPUNIT_ASSERT(bRet);
+        CPPUNIT_ASSERT(aFoo.equalsL(RTL_CONSTASCII_STRINGPARAM("bar")));
+        CPPUNIT_ASSERT(aMemStream.good());
+
+        bRet = aMemStream.ReadLine(aFoo);
+        CPPUNIT_ASSERT(bRet);
+        CPPUNIT_ASSERT(aFoo.isEmpty());
+        CPPUNIT_ASSERT(aMemStream.good());
+
+        bRet = aMemStream.ReadLine(aFoo);
+        CPPUNIT_ASSERT(!bRet);
+        CPPUNIT_ASSERT(aFoo.isEmpty());
+        CPPUNIT_ASSERT(aMemStream.eof());
+
+        foo[3] = 0; //test reading embedded nulls
+
+        aMemStream.Seek(0);
+        bRet = aMemStream.ReadLine(aFoo);
+        CPPUNIT_ASSERT(bRet);
+        //This is the weird current behavior where an embedded null is read but
+        //discarded
+        CPPUNIT_ASSERT(aFoo.equalsL(RTL_CONSTASCII_STRINGPARAM("foobar")));
+        CPPUNIT_ASSERT(aMemStream.good());
+
+        std::string sStr(RTL_CONSTASCII_STRINGPARAM(foo));
+        std::istringstream iss(sStr, std::istringstream::in);
+        std::getline(iss, sStr, '\n');
+        //embedded null read as expected
+        CPPUNIT_ASSERT(sStr.size() == 7 && sStr[3] == 0);
+        CPPUNIT_ASSERT(iss.good());
+
+        bRet = aMemStream.ReadLine(aFoo);
+        CPPUNIT_ASSERT(bRet);
+        CPPUNIT_ASSERT(aFoo.isEmpty());
+        CPPUNIT_ASSERT(aMemStream.good());
+
+        std::getline(iss, sStr, '\n');
+        CPPUNIT_ASSERT(sStr.empty());
+        CPPUNIT_ASSERT(iss.good());
+
+        bRet = aMemStream.ReadLine(aFoo);
+        CPPUNIT_ASSERT(!bRet);
+        CPPUNIT_ASSERT(aFoo.isEmpty());
+        CPPUNIT_ASSERT(aMemStream.eof() && !aMemStream.bad());
+
+        std::getline(iss, sStr, '\n');
+        CPPUNIT_ASSERT(sStr.empty());
+        CPPUNIT_ASSERT(iss.eof() && !iss.bad());
+
+        }
+
     CPPUNIT_TEST_SUITE_REGISTRATION(Test);
 }