v2-0001-handle-openssl-returning-errno-zero.patch

diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 6b8125695a..3ec17fb11a 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -460,6 +460,7 @@ aloop:
 	 * per-thread error queue following another call to an OpenSSL I/O
 	 * routine.
 	 */
+	errno = 0;
 	ERR_clear_error();
 	r = SSL_accept(port->ssl);
 	if (r <= 0)
@@ -496,7 +497,7 @@ aloop:
 										 WAIT_EVENT_SSL_OPEN_SERVER);
 				goto aloop;
 			case SSL_ERROR_SYSCALL:
-				if (r < 0)
+				if (r < 0 && errno != 0)
 					ereport(COMMERROR,
 							(errcode_for_socket_access(),
 							 errmsg("could not accept SSL connection: %m")));
@@ -732,7 +733,7 @@ be_tls_read(Port *port, void *ptr, size_t len, int *waitfor)
 			break;
 		case SSL_ERROR_SYSCALL:
 			/* leave it to caller to ereport the value of errno */
-			if (n != -1)
+			if (n != -1 || errno == 0)
 			{
 				errno = ECONNRESET;
 				n = -1;
@@ -791,7 +792,7 @@ be_tls_write(Port *port, void *ptr, size_t len, int *waitfor)
 			break;
 		case SSL_ERROR_SYSCALL:
 			/* leave it to caller to ereport the value of errno */
-			if (n != -1)
+			if (n != -1 || errno == 0)
 			{
 				errno = ECONNRESET;
 				n = -1;
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index e669bdbf1d..9ebebea777 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -200,7 +200,7 @@ rloop:
 			 */
 			goto rloop;
 		case SSL_ERROR_SYSCALL:
-			if (n < 0)
+			if (n < 0 && SOCK_ERRNO != 0)
 			{
 				result_errno = SOCK_ERRNO;
 				if (result_errno == EPIPE ||
@@ -301,7 +301,7 @@ pgtls_write(PGconn *conn, const void *ptr, size_t len)
 			n = 0;
 			break;
 		case SSL_ERROR_SYSCALL:
-			if (n < 0)
+			if (n < 0 && SOCK_ERRNO != 0)
 			{
 				result_errno = SOCK_ERRNO;
 				if (result_errno == EPIPE || result_errno == ECONNRESET)
@@ -1510,11 +1510,12 @@ open_client_SSL(PGconn *conn)
 					 * was using the system CA pool. For other errors, log
 					 * them using the normal SYSCALL logging.
 					 */
-					if (!save_errno && vcode == X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY &&
+					if (save_errno == 0 &&
+						vcode == X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY &&
 						strcmp(conn->sslrootcert, "system") == 0)
 						libpq_append_conn_error(conn, "SSL error: certificate verify failed: %s",
 												X509_verify_cert_error_string(vcode));
-					else if (r == -1)
+					else if (r == -1 && save_errno != 0)
 						libpq_append_conn_error(conn, "SSL SYSCALL error: %s",
 												SOCK_STRERROR(save_errno, sebuf, sizeof(sebuf)));
 					else