MDEV-11111: wire the launcher into mysql_server_init()

Glue (embedded_glue.c) registers the launcher with libmariadb through
mariadb_set_embedded_hooks(), so that the plain client API is enough:
mysql_server_init(argc, argv) starts the server, connecting to localhost
reaches it, mysql_server_end() stops it. launcher_test now uses only that.

Points libmariadb at the MDEV-11111-embedded-hooks branch (57875d2c).
That commit exists only locally and must be pushed to the libmariadb
repository before this one can be.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

libmysqld/launcher/embedded_glue.c

@@ -0,0 +1,58 @@
+/* Copyright (c) 2026, MariaDB plc
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335  USA */
+
+/*
+  MDEV-11111: connect the launcher to libmariadb.
+
+  After mariadb_embedded_register(), the ordinary client API is enough:
+  mysql_server_init(argc, argv, groups) starts the server, mysql_real_connect()
+  to the local host (no host, "localhost", "." on Windows) reaches it, and
+  mysql_server_end() stops it.
+
+  A shared libmariadbd is built with MARIADB_EMBEDDED_AUTOREGISTER, so
+  merely loading it registers the hooks; a static build calls
+  mariadb_embedded_register() explicitly.
+*/
+
+#include <stdio.h>
+#include <mysql.h>
+#include "embedded_launcher.h"
+
+static int init_hook(int argc, char **argv, char **groups)
+{
+  if (mariadb_embedded_start(argc, argv, groups))
+  {
+    fprintf(stderr, "mysql_server_init: %s\n", mariadb_embedded_error());
+    return 1;
+  }
+  return 0;
+}
+
+static void end_hook(void)
+{
+  mariadb_embedded_stop();
+}
+
+void mariadb_embedded_register(void)
+{
+  mariadb_set_embedded_hooks(init_hook, end_hook, mariadb_embedded_socket);
+}
+
+#if defined(MARIADB_EMBEDDED_AUTOREGISTER) && defined(__GNUC__)
+__attribute__((constructor)) static void autoregister(void)
+{
+  mariadb_embedded_register();
+}
+#endif

libmysqld/launcher/embedded_launcher.h

@@ -56,6 +56,10 @@ const char *mariadb_embedded_socket(void);
 /* Last error message */
 const char *mariadb_embedded_error(void);
 
+/* Register the launcher with libmariadb (embedded_glue.c), so that
+   mysql_server_init()/mysql_server_end() start and stop the server */
+void mariadb_embedded_register(void);
+
 #ifdef __cplusplus
 }
 #endif

libmysqld/launcher/launcher_test.c

@@ -1,20 +1,20 @@
 /*
-  MDEV-11111: smoke test for the embedded launcher.
+  MDEV-11111: smoke test for the embedded server.
   Usage: launcher_test [server options...]
-  Starts the server, runs a query through the normal client library over the
-  private socket, stops the server.
+  Uses only the ordinary client API: mysql_server_init() starts the server,
+  a connection to "localhost" reaches it, mysql_server_end() stops it.
 */
 #include <stdio.h>
 #include <stdlib.h>
-#include <mysql.h>
-#include "embedded_launcher.h"
 #ifdef _WIN32
 #include <windows.h>
-#define Sleep_or_pause() Sleep(1000)
+#define pause_1s() Sleep(1000)
 #else
 #include <unistd.h>
-#define Sleep_or_pause() sleep(1)
+#define pause_1s() sleep(1)
 #endif
+#include <mysql.h>
+#include "embedded_launcher.h"
 
 int main(int argc, char **argv)
 {
@@ -23,23 +23,12 @@ int main(int argc, char **argv)
   MYSQL_ROW row;
   int rc= 1;
 
-  if (mariadb_embedded_start(argc, argv, NULL))
-  {
-    fprintf(stderr, "start failed: %s\n", mariadb_embedded_error());
+  mariadb_embedded_register(); /* not needed with a shared libmariadbd */
+  if (mysql_server_init(argc, argv, NULL))
     return 1;
-  }
-  printf("socket: %s\n", mariadb_embedded_socket());
 
-  mysql_library_init(0, NULL, NULL); /* reads MARIADB_UNIX_PORT */
   m= mysql_init(NULL);
-#ifdef _WIN32
-  /* libmariadb ignores MARIADB_UNIX_PORT for named pipes, pass it explicitly */
-  const char *host= ".";
-#else
-  const char *host= "localhost"; /* default socket: $MARIADB_UNIX_PORT */
-#endif
-  if (!mysql_real_connect(m, host, "root", NULL, NULL, 0,
-                          mariadb_embedded_socket(), 0))
+  if (!mysql_real_connect(m, "localhost", "root", NULL, NULL, 0, NULL, 0))
     fprintf(stderr, "connect failed: %s\n", mysql_error(m));
   else if (mysql_query(m, "SELECT @@version, 1+1") ||
            !(res= mysql_store_result(m)))
@@ -53,10 +42,9 @@ int main(int argc, char **argv)
   }
   if (getenv("LAUNCHER_TEST_HANG")) /* to kill us and watch the server */
     for (;;)
-      Sleep_or_pause();
+      pause_1s();
   mysql_close(m);
-  mysql_library_end();
-  mariadb_embedded_stop();
+  mysql_server_end();
   puts(rc ? "FAIL" : "OK");
   return rc;
 }