Added assignment to MString from ZString operator=.

MString.cpp

@@ -80,6 +80,13 @@ namespace coreutils {
       length = value.getLength();
       return *this;
    }
+
+   MString &MString::operator=(coreutils::ZString value) {
+      setSize(value.getLength());
+      memcpy(data, value.getData(), value.getLength());
+      length = value.getLength();
+      return *this;
+   }
    
    MString &MString::operator=(const char *value) {
       int len = strlen(value);

MString.h

@@ -94,11 +94,10 @@ namespace coreutils
       ///
       /// Assignment operator will copy data to backing store.
       ///
-      
-      //      MString& operator=(coreutils::ZString& data);
-      
+            
       MString &operator=(coreutils::MString data);
-      
+      MString &operator=(coreutils::ZString data);
+
       ///
       /// Assignment operator will copy data to backing store.
       ///

testing/mstring_test.cpp

@@ -57,7 +57,15 @@ int main(int argc, char **argv) {
    std::cout << ">" << test10 << "<" << std::endl;
    test10 = "";
    std::cout << ">" << test10 << "<" << std::endl;
- 
+
+   // Assign from ZString tests.
+
+   coreutils::ZString test20("This is a zstring");
+   coreutils::MString test21;
+   test21 = test20;
+   std::cout << "mstring = zstring: [" << test21 <<  "]" << std::endl;
+   
+   
    return 0;
 }