diff --git a/include/wx/catch_cppunit.h b/include/wx/catch_cppunit.h
index 22ebcf12f9..66e660b158 100644
--- a/include/wx/catch_cppunit.h
+++ b/include/wx/catch_cppunit.h
@@ -73,6 +73,32 @@ namespace Catch
             return wxString(ucr).ToStdString(wxConvUTF8);
         }
     };
+
+    // While this conversion already works due to the existence of the stream
+    // insertion operator for wxString, define a custom one making it more
+    // obvious when strings containing non-printable characters differ.
+    template <>
+    struct StringMaker<wxString>
+    {
+        static std::string convert(const wxString& wxs)
+        {
+            std::string s;
+            s.reserve(wxs.length());
+            for ( wxString::const_iterator i = wxs.begin();
+                  i != wxs.end();
+                  ++i )
+            {
+#if wxUSE_UNICODE
+                if ( !iswprint(*i) )
+                    s += wxString::Format("\\u%04X", *i).ToStdString();
+                else
+#endif // wxUSE_UNICODE
+                    s += *i;
+            }
+
+            return s;
+        }
+    };
 }
 
 // Use a different namespace for our mock ups of the real declarations in
diff --git a/include/wx/string.h b/include/wx/string.h
index b80998cc44..a4e682b8ff 100644
--- a/include/wx/string.h
+++ b/include/wx/string.h
@@ -1162,6 +1162,9 @@ public:
   wxString(const wxScopedWCharBuffer& buf)
     { assign(buf.data(), buf.length()); }
 
+  wxString(const wxScopedCharBuffer& buf, const wxMBConv& conv)
+    { assign(buf, conv); }
+
     // NB: this version uses m_impl.c_str() to force making a copy of the
     //     string, so that "wxString(str.c_str())" idiom for passing strings
     //     between threads works
@@ -2539,6 +2542,13 @@ public:
     { return assign(str.AsString()); }
   wxString& assign(const wxScopedCharBuffer& str)
     { return assign(str.data(), str.length()); }
+  wxString& assign(const wxScopedCharBuffer& buf, const wxMBConv& conv)
+  {
+      SubstrBufFromMB str(ImplStr(buf.data(), buf.length(), conv));
+      m_impl.assign(str.data, str.len);
+
+      return *this;
+  }
   wxString& assign(const wxScopedWCharBuffer& str)
     { return assign(str.data(), str.length()); }
   wxString& assign(const wxCStrData& str, size_t len)
diff --git a/src/common/file.cpp b/src/common/file.cpp
index 9da9aba608..0e976273dc 100644
--- a/src/common/file.cpp
+++ b/src/common/file.cpp
@@ -281,8 +281,7 @@ bool wxFile::ReadAll(wxString *str, const wxMBConv& conv)
         length -= nread;
     }
 
-    wxString strTmp(buf, conv, length);
-    str->swap(strTmp);
+    str->assign(buf, conv);
 
     return true;
 }
diff --git a/tests/file/filetest.cpp b/tests/file/filetest.cpp
index 31870164c3..fdad2d8e4a 100644
--- a/tests/file/filetest.cpp
+++ b/tests/file/filetest.cpp
@@ -116,6 +116,16 @@ void FileTestCase::DoRoundTripTest(const wxMBConv& conv)
         wxString dataReadBack(buf, conv, len);
         CPPUNIT_ASSERT_EQUAL( data, dataReadBack );
     }
+
+    {
+        wxFile fin(tf.GetName(), wxFile::read);
+        CPPUNIT_ASSERT( fin.IsOpened() );
+
+        wxString dataReadBack;
+        CPPUNIT_ASSERT( fin.ReadAll(&dataReadBack, conv) );
+
+        CPPUNIT_ASSERT_EQUAL( data, dataReadBack );
+    }
 }
 
 #endif // wxUSE_UNICODE