Add test case calling ssl_set_hostname twice

Add a test case calling ssl_set_hostname twice to test_suite_ssl.
When run in CMake build mode ASan, this catches the current leak,
but will hopefully be fine with the new version.
diff --git a/tests/suites/test_suite_ssl.data b/tests/suites/test_suite_ssl.data
index a39f6f0..b92c1fe 100644
--- a/tests/suites/test_suite_ssl.data
+++ b/tests/suites/test_suite_ssl.data
@@ -54,3 +54,6 @@
 
 SSL DTLS replay: big jump then just delayed
 ssl_dtls_replay:"abcd12340000,abcd12340100":"abcd123400ff":0
+
+SSL SET_HOSTNAME memory leak: call ssl_set_hostname twice
+ssl_set_hostname_twice:"server0":"server1"
diff --git a/tests/suites/test_suite_ssl.function b/tests/suites/test_suite_ssl.function
index 8d3448c..60683af 100644
--- a/tests/suites/test_suite_ssl.function
+++ b/tests/suites/test_suite_ssl.function
@@ -40,3 +40,16 @@
     mbedtls_ssl_config_free( &conf );
 }
 /* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_X509_CRT_PARSE_C */
+void ssl_set_hostname_twice( char *hostname0, char *hostname1 )
+{
+    mbedtls_ssl_context ssl;
+    mbedtls_ssl_init( &ssl );
+
+    TEST_ASSERT( mbedtls_ssl_set_hostname( &ssl, hostname0 ) == 0 );
+    TEST_ASSERT( mbedtls_ssl_set_hostname( &ssl, hostname1 ) == 0 );
+
+    mbedtls_ssl_free( &ssl );
+}
+/* END_CASE */
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