Remove mysqli embedded server support

This code is not compatible with PHP 7.0. The fact that nobody
complained that the mysqli embedded server functionality doesn't
build anymore seems like a strong signal that we can drop it...

UPGRADING

@@ -40,6 +40,10 @@ PHP 7.4 UPGRADE NOTES
   . The default parameter value of idn_to_ascii() and idn_to_utf8() is now
     INTL_IDNA_VARIANT_UTS46 instead of the deprecated INTL_IDNA_VARIANT_2003.
 
+- MySQLi:
+  . The embedded server functionality has been removed. It was broken since
+    at least PHP 7.0.
+
 - Openssl:
   . The openssl_random_pseudo_bytes() function will now throw an exception in
     error situations, similar to random_bytes(). In particular, an Error is

ext/mysqli/config.m4

@@ -32,11 +32,6 @@ PHP_ARG_WITH(mysqli, for MySQLi support,
                           to mysql_config.  If no value or mysqlnd is passed
                           as FILE, the MySQL native driver will be used])
 
-PHP_ARG_ENABLE(embedded_mysqli, whether to enable embedded MySQLi support,
-[  --enable-embedded-mysqli
-                          MYSQLi: Enable embedded support
-                          Note: Does not work with MySQL native driver!], no, no)
-
 dnl ext/pdo_mysql/config.m4 also depends on this configure option.
 PHP_ARG_WITH(mysql-sock, for specified location of the MySQL UNIX socket,
 [  --with-mysql-sock[=SOCKPATH]
@@ -52,12 +47,7 @@ elif test "$PHP_MYSQLI" != "no"; then
   MYSQL_CONFIG=$PHP_MYSQLI
 
   MYSQL_LIB_NAME='mysqlclient'
-  if test "$PHP_EMBEDDED_MYSQLI" = "yes"; then
-    AC_DEFINE(HAVE_EMBEDDED_MYSQLI, 1, [embedded MySQL support enabled])
-    MYSQL_LIB_CFG='--libmysqld-libs'
-    dnl mysqlnd doesn't support embedded, so we have to add some extra stuff
-    mysqli_extra_sources="mysqli_embedded.c"
-  elif test "$enable_maintainer_zts" = "yes"; then
+  if test "$enable_maintainer_zts" = "yes"; then
     MYSQL_LIB_CFG='--libs_r'
     MYSQL_LIB_NAME='mysqlclient_r'
   else
@@ -116,7 +106,7 @@ if test "$PHP_MYSQLI" != "no"; then
 
   mysqli_sources="mysqli.c mysqli_api.c mysqli_prop.c mysqli_nonapi.c \
                   mysqli_fe.c mysqli_report.c mysqli_driver.c mysqli_warning.c \
-                  mysqli_exception.c mysqli_result_iterator.c $mysqli_extra_sources"
+                  mysqli_exception.c mysqli_result_iterator.c"
   PHP_NEW_EXTENSION(mysqli, $mysqli_sources, $ext_shared,, -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1)
   PHP_SUBST(MYSQLI_SHARED_LIBADD)
   PHP_INSTALL_HEADERS([ext/mysqli/php_mysqli_structs.h])

ext/mysqli/mysqli.c

@@ -546,11 +546,7 @@ static PHP_GINIT_FUNCTION(mysqli)
 	mysqli_globals->report_mode = 0;
 	mysqli_globals->report_ht = 0;
 	mysqli_globals->allow_local_infile = 0;
-#ifdef HAVE_EMBEDDED_MYSQLI
-	mysqli_globals->embedded = 1;
-#else
 	mysqli_globals->embedded = 0;
-#endif
 	mysqli_globals->rollback_on_cached_plink = FALSE;
 }
 /* }}} */

ext/mysqli/mysqli_driver.c

@@ -84,11 +84,7 @@ static int driver_report_write(mysqli_object *obj, zval *value)
 /* {{{ property driver_embedded_read */
 static zval *driver_embedded_read(mysqli_object *obj, zval *retval)
 {
-#ifdef HAVE_EMBEDDED_MYSQLI
-	ZVAL_TRUE(retval);
-#else
 	ZVAL_FALSE(retval);
-#endif
 	return retval;
 }
 /* }}} */
@@ -146,10 +142,6 @@ const mysqli_property_entry mysqli_driver_property_entries[] = {
 /* {{{ mysqli_driver_methods[]
  */
 const zend_function_entry mysqli_driver_methods[] = {
-#if defined(HAVE_EMBEDDED_MYSQLI)
-	PHP_FALIAS(embedded_server_start, mysqli_embedded_server_start, NULL)
-	PHP_FALIAS(embedded_server_end, mysqli_embedded_server_end, NULL)
-#endif
 	PHP_FE_END
 };
 /* }}} */

ext/mysqli/mysqli_fe.c

@@ -420,10 +420,6 @@ const zend_function_entry mysqli_functions[] = {
 	PHP_FE(mysqli_data_seek,							arginfo_mysqli_data_seek)
 	PHP_FE(mysqli_dump_debug_info,						arginfo_mysqli_only_link)
 	PHP_FE(mysqli_debug,								arginfo_mysqli_debug)
-#if defined(HAVE_EMBEDDED_MYSQLI)
-	PHP_FE(mysqli_embedded_server_end,					NULL)
-	PHP_FE(mysqli_embedded_server_start,				NULL)
-#endif
 	PHP_FE(mysqli_errno,								arginfo_mysqli_only_link)
 	PHP_FE(mysqli_error,								arginfo_mysqli_only_link)
 	PHP_FE(mysqli_error_list,							arginfo_mysqli_only_link)

ext/mysqli/mysqli_nonapi.c

@@ -219,15 +219,6 @@ void mysqli_common_connect(INTERNAL_FUNCTION_PARAMETERS, zend_bool is_real_conne
 		new_connection = TRUE;
 	}
 
-#ifdef HAVE_EMBEDDED_MYSQLI
-	if (hostname_len) {
-		unsigned int external=1;
-		mysql_options(mysql->mysql, MYSQL_OPT_USE_REMOTE_CONNECTION, (char *)&external);
-	} else {
-		mysql_options(mysql->mysql, MYSQL_OPT_USE_EMBEDDED_CONNECTION, 0);
-	}
-#endif
-
 #if !defined(MYSQLI_USE_MYSQLND)
 	/* BC for prior to bug fix #53425 */
 	flags |= CLIENT_MULTI_RESULTS;