Merge pull request #4259 from LMESTM/fix_Stream_issue687

Add error check in Stream constructor

Author: adbridge

platform/Stream.cpp

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 #include "platform/Stream.h"
+#include "platform/mbed_error.h"
+#include <errno.h>
 
 namespace mbed {
 
@@ -23,7 +25,11 @@ Stream::Stream(const char *name) : FileLike(name), _file(NULL) {
     char buf[12]; /* :0x12345678 + null byte */
     std::sprintf(buf, ":%p", this);
     _file = std::fopen(buf, "w+");
-    mbed_set_unbuffered_stream(_file);
+    if (_file) {
+        mbed_set_unbuffered_stream(_file);
+    } else {
+        error("Stream obj failure, errno=%d\r\n", errno);
+    }
 }
 
 Stream::~Stream() {