Refs #21362. Fix behavior.

Signed-off-by: Miguel Company <[email protected]>

include/fastcdr/Cdr.h

@@ -706,10 +706,7 @@ class Cdr
      */
     TEMPLATE_SPEC
     Cdr& serialize(
-            const std::string& string_t)
-    {
-        return serialize(string_t.c_str());
-    }
+            const std::string& string_t);
 
     /*!
      * @brief This function serializes a std::wstring.

src/cpp/Cdr.cpp

@@ -14,6 +14,7 @@
 
 #include <cstring>
 #include <limits>
+#include <string>
 
 #include <fastcdr/Cdr.h>
 
@@ -851,6 +852,27 @@ Cdr& Cdr::serialize(
     return *this;
 }
 
+TEMPLATE_SPEC
+Cdr& Cdr::serialize(
+        const std::string& string_t)
+{
+    // An empty string is serialized as a 0 length string.
+    if (string_t.empty())
+    {
+        return serialize(static_cast<uint32_t>(0));
+    }
+
+    // Check there are no null characters in the string.
+    const char* c_str = string_t.c_str();
+    const auto str_len = strlen(c_str);
+    if (string_t.size() > str_len)
+    {
+        throw BadParamException("The string contains null characters");
+    }
+
+    return serialize_sequence(c_str, str_len + 1);
+}
+
 Cdr& Cdr::serialize_array(
         const bool* bool_t,
         size_t num_elements)