Add patch to fix -fpermissive, fixes FTBFS for Fedora 30

percona-xtrabackup-2.3.6-fix-fpermissive.patch

@@ -0,0 +1,13 @@
+Index: percona-xtrabackup-7686bfc6e5a5163f73e2adea38eac0da06c9898e/sql/sql_acl.cc
+===================================================================
+--- percona-xtrabackup-7686bfc6e5a5163f73e2adea38eac0da06c9898e.orig/sql/sql_acl.cc
++++ percona-xtrabackup-7686bfc6e5a5163f73e2adea38eac0da06c9898e/sql/sql_acl.cc
+@@ -3014,7 +3014,7 @@ static int replace_user_table(THD *thd,
+       * An empty password is considered to be of mysql_native type.
+     */
+     
+-    if (combo->plugin.str == NULL || combo->plugin.str == '\0')
++    if (combo->plugin.str == NULL || *(combo->plugin.str) == '\0')
+     {
+       if (combo->uses_identified_by_password_clause)
+       {

percona-xtrabackup.spec

@@ -18,6 +18,7 @@ URL: http://www.percona.com/software/percona-xtrabackup/
 Source: https://github.com/percona/%{name}/archive/%{commit}/%{name}-%{commit}.tar.gz
 Patch0: percona-xtrabackup-gcc7-flags.patch
 Patch1: percona-xtrabackup-2.3.6-explicit-shebangs.patch
+Patch2: percona-xtrabackup-2.3.6-fix-fpermissive.patch
 Provides: xtrabackup >= 2.0.0
 Provides: %{name}-%{pxbu_major_minor}
 Obsoletes: xtrabackup < 2.0.0
@@ -59,6 +60,7 @@ This package contains the test suite for Percona Xtrabackup
 %setup -qn %{name}-%{commit}
 %patch0 -p1
 %patch1 -p1
+%patch2 -p1
 
 # fails build
 # build for mariadb version
@@ -133,6 +135,7 @@ popd
 %changelog
 * Fri Jan 04 2019 Björn Esser <besser82@fedoraproject.org> - 2.3.6-11
 - Add patch to use explicit shebangs, fixes FTBFS for Fedora 30
+- Add patch to fix -fpermissive, fixes FTBFS for Fedora 30
 - Apply proper buildflags
 - Modernize spec-file