Add test case for invalid copy

Author: giulcioffi

test/src/String/test_operators.cpp

@@ -112,4 +112,28 @@ TEST_CASE ("Testing & String::operator = (StringSumHelper &&rval)", "[String-ope
   arduino::String str = (str1+ch);
   REQUIRE(str.compareTo("Hello!") == 0);
   */
+}
+
+TEST_CASE ("Testing & String::operator = (const String &)", "[String-operator+-13]")
+{
+  char *buffer1 = (char *)malloc(sizeof("Hello"));
+  strcpy(buffer1, "Hello");
+  arduino::String str1(buffer1);
+
+  char *buffer2 = (char *)malloc(sizeof("Hello"));
+  strcpy(buffer2, "Hello");
+  arduino::String str2(buffer2);
+
+  //buffer2 = (char *)realloc(buffer, 0);
+  free(buffer2);
+  //arduino::String str1("Hello");
+  str1 = str2;
+  REQUIRE(str1.compareTo("Hello") == 0);
+  free(buffer1);
+  /*
+  arduino::String str1;
+  char ch='!';
+  arduino::String str = (str1+ch);
+  REQUIRE(str.compareTo("Hello!") == 0);
+  */
 }