Updated Espressif SDK no longer needs this hack.

pal/src/tlsio_openssl_compact.c

@@ -649,7 +649,9 @@ static void dowork_poll_open_ssl(TLS_IO_INSTANCE* tls_io_instance)
     // but by experiment, 0 is the success result, at least when using
     // SSL_set_fd instead of custom BIO.
     // https://www.openssl.org/docs/man1.0.2/ssl/SSL_connect.html
-    if (connect_result == 1 || connect_result == 0)
+    // Update: Later versions of the Espressif SDK seem to adhere to the
+    // documentation.
+    if (connect_result == 1)
     {
         /* Codes_SRS_TLSIO_30_080: [ The tlsio_dowork shall establish a TLS connection using the hostName and port provided during tlsio_open. ]*/
         // Connect succeeded

sdk_tests/tlsio_openssl_compact_ut/ssl_impl.h

@@ -16,7 +16,7 @@
 #define SSL_Good_Ptr (void*)22
 #define SSL_Good_Context_Ptr (SSL_CTX*)33
 #define SSL_Good_Socket 44
-#define SSL_CONNECT_SUCCESS 0
+#define SSL_CONNECT_SUCCESS 1
 #define SSL_SET_FD_SUCCESS 1
 #define SSL_SET_FD_FAILURE 0
 #define SSL_READ_NO_DATA 0