Handle strings with embedded NULs in wxDataStream

Read/write the entire string and not just the part until the first NUL in it.

Closes #17556.

docs/changes.txt

@@ -72,6 +72,7 @@ All:
 - Add wxFileType::GetExpandedCommand() (troelsk).
 - Make it easier to convert to/from UTF-8-encoded std::string (ARATA Mizuki).
 - Add support for loading dynamic lexer in wxStyledTextCtrl (New Pagodi).
+- Handle strings with embedded NULs in wxDataStream (Nitch).
 
 All (GUI):
 

src/common/datstrm.cpp

@@ -187,7 +187,7 @@ wxString wxDataInputStream::ReadString()
         if ( tmp )
         {
             m_input->Read(tmp.data(), len);
-            ret = m_conv->cMB2WX(tmp.data());
+            ret = m_conv->cMB2WC(tmp.data(), len, NULL);
         }
 #else
         wxStringBuffer buf(ret, len);
@@ -590,10 +590,11 @@ void wxDataOutputStream::WriteString(const wxString& string)
 {
 #if wxUSE_UNICODE
   const wxWX2MBbuf buf = string.mb_str(*m_conv);
+  size_t len = buf.length();
 #else
   const wxWX2MBbuf buf = string.mb_str();
+  size_t len = string.size();
 #endif
-  size_t len = strlen(buf);
   Write32(len);
   if (len > 0)
       m_output->Write(buf, len);

tests/streams/datastreamtest.cpp

@@ -39,6 +39,7 @@ private:
     CPPUNIT_TEST_SUITE( DataStreamTestCase );
         CPPUNIT_TEST( FloatRW );
         CPPUNIT_TEST( DoubleRW );
+        CPPUNIT_TEST( StringRW );
 #if wxUSE_LONGLONG
         CPPUNIT_TEST( LongLongRW );
 #endif
@@ -66,6 +67,7 @@ private:
 
     void FloatRW();
     void DoubleRW();
+    void StringRW();
 #if wxUSE_LONGLONG
     void LongLongRW();
 #endif
@@ -236,6 +238,19 @@ void DataStreamTestCase::DoubleRW()
     CPPUNIT_ASSERT( TestFloatRW(21321343431.1232143432) == 21321343431.1232143432 );
 }
 
+void DataStreamTestCase::StringRW()
+{
+    wxString s(wxT("Test1"));
+    CPPUNIT_ASSERT_EQUAL( TestRW(s), s );
+
+    s.append(2, wxT('\0'));
+    s.append(wxT("Test2"));
+    CPPUNIT_ASSERT_EQUAL( TestRW(s), s );
+
+    s = wxString::FromUTF8("\xc3\xbc"); // U+00FC LATIN SMALL LETTER U WITH DIAERESIS
+    CPPUNIT_ASSERT_EQUAL( TestRW(s), s );
+}
+
 #if wxUSE_LONGLONG
 void DataStreamTestCase::LongLongRW()
 {