MDEV-37483 - fix output differences Linux vs Windows in the test

- Do not mix latin1 and utf8 in the test and result file.
  Not only it looks strange, and it does not work on Windows either.

- Fix --default-character-set usage in mariadb-import.
  Prior to patch   it was just using platform default when communicating
  with server. Now, it uses the charset provided by the option.

- Use --default-character-set=utf8mb4 in test, to have
  uniform output across different OSes.

client/mysqlimport.c

@@ -343,8 +343,8 @@ static int write_to_table(char *filename, MYSQL *mysql)
   if (strchr(tablename, '@'))
   {
     uint errors, len;
-    const char *csname= my_default_csname(); /* see MYSQL_SET_CHARSET_NAME */
-    CHARSET_INFO *cs= get_charset_by_csname(csname,  MY_CS_PRIMARY, MYF(0));
+    CHARSET_INFO *cs=
+        get_charset_by_csname(default_charset, MY_CS_PRIMARY, MYF(0));
     len= my_convert(escaped_name, sizeof(escaped_name) - 1, cs, tablename,
                     (uint32)strlen(tablename), &my_charset_filename, &errors);
     if (!errors)
@@ -498,7 +498,7 @@ static MYSQL *db_connect(char *host, char *database,
     mysql_options(mysql, MYSQL_DEFAULT_AUTH, opt_default_auth);
   if (!strcmp(default_charset,MYSQL_AUTODETECT_CHARSET_NAME))
     default_charset= (char *)my_default_csname();
-  mysql_options(mysql, MYSQL_SET_CHARSET_NAME, my_default_csname());
+  mysql_options(mysql, MYSQL_SET_CHARSET_NAME, default_charset);
   mysql_options(mysql, MYSQL_OPT_CONNECT_ATTR_RESET, 0);
   mysql_options4(mysql, MYSQL_OPT_CONNECT_ATTR_ADD,
                  "program_name", "mysqlimport");

mysql-test/main/mysqldump.result

@@ -6627,33 +6627,32 @@ drop table t1;
 #
 # MDEV-37483 mariadb-dump -T doesn't convert table names
 #
-set names latin1;
 create database foo;
 use foo;
-create table `con_schöne_grüße` (a int) select 1 as a;
+create table `con_schöne_grüße` (a int) select 1 as a;
 create table `con` (b int) select 2 as b;
 create table `con/bar` (c int) select 3 as c;
-create table `con@home` (d int) select 4 as d;
+create table `con@fame` (d int) select 4 as d;
 drop database foo;
 use test;
 con@002fbar.sql
 con@002fbar.txt
 con@@@.sql
 con@@@.txt
-con@home.sql
-con@home.txt
+con@fame.sql
+con@fame.txt
 con_sch@1ine_gr@1o@1je.sql
 con_sch@1ine_gr@1o@1je.txt
 show tables;
 Tables_in_test
 con
 con/bar
-con@home
-con_schöne_grüße
+con@fame
+con_schöne_grüße
 test.con: Records: 1  Deleted: 0  Skipped: 0  Warnings: 0
 test.con/bar: Records: 1  Deleted: 0  Skipped: 0  Warnings: 0
-test.con@home: Records: 1  Deleted: 0  Skipped: 0  Warnings: 0
-select * from `con_schöne_grüße`;
+test.con@fame: Records: 1  Deleted: 0  Skipped: 0  Warnings: 0
+select * from `con_schöne_grüße`;
 a
 1
 select * from `con`;
@@ -6662,11 +6661,11 @@ b
 select * from `con/bar`;
 c
 3
-select * from `con@home`;
+select * from `con@fame`;
 d
 4
-drop table `con_schöne_grüße`;
+drop table `con_schöne_grüße`;
 drop table `con`;
 drop table `con/bar`;
-drop table `con@home`;
+drop table `con@fame`;
 # End of 10.6 tests

mysql-test/main/mysqldump.test

@@ -3039,24 +3039,23 @@ drop table t1;
 --echo #
 --echo # MDEV-37483 mariadb-dump -T doesn't convert table names
 --echo #
-set names latin1;
 create database foo;
 use foo;
 
-create table `con_schöne_grüße` (a int) select 1 as a;
+create table `con_schöne_grüße` (a int) select 1 as a;
 create table `con` (b int) select 2 as b;
 create table `con/bar` (c int) select 3 as c;
-create table `con@home` (d int) select 4 as d;
+create table `con@fame` (d int) select 4 as d;
 exec $MYSQL_DUMP foo --tab $MYSQLTEST_VARDIR/tmp;
 drop database foo;
 use test;
-move_file $MYSQLTEST_VARDIR/tmp/con@0040home.sql $MYSQLTEST_VARDIR/tmp/con@home.sql;
-move_file $MYSQLTEST_VARDIR/tmp/con@0040home.txt $MYSQLTEST_VARDIR/tmp/con@home.txt;
+move_file $MYSQLTEST_VARDIR/tmp/con@0040fame.sql $MYSQLTEST_VARDIR/tmp/con@fame.sql;
+move_file $MYSQLTEST_VARDIR/tmp/con@0040fame.txt $MYSQLTEST_VARDIR/tmp/con@fame.txt;
 list_files $MYSQLTEST_VARDIR/tmp con*;
 exec $MYSQL test < $MYSQLTEST_VARDIR/tmp/con@@@.sql;
 exec $MYSQL test < $MYSQLTEST_VARDIR/tmp/con@002fbar.sql;
 exec $MYSQL test < $MYSQLTEST_VARDIR/tmp/con_sch@1ine_gr@1o@1je.sql;
-exec $MYSQL test < $MYSQLTEST_VARDIR/tmp/con@home.sql;
+exec $MYSQL test < $MYSQLTEST_VARDIR/tmp/con@fame.sql;
 show tables;
 exec $MYSQL_IMPORT test $MYSQLTEST_VARDIR/tmp/con@@@.txt;
 exec $MYSQL_IMPORT test $MYSQLTEST_VARDIR/tmp/con@002fbar.txt;
@@ -3064,16 +3063,16 @@ if (`select @@version like '10.6.%'`) {
 # utf8 console output on Windows is fixed in MDEV-26713, until then
 --disable_result_log
 }
-exec $MYSQL_IMPORT test $MYSQLTEST_VARDIR/tmp/con_sch@1ine_gr@1o@1je.txt;
+exec $MYSQL_IMPORT --default-character-set=utf8mb4 test $MYSQLTEST_VARDIR/tmp/con_sch@1ine_gr@1o@1je.txt;
 --enable_result_log
-exec $MYSQL_IMPORT test $MYSQLTEST_VARDIR/tmp/con@home.txt;
-select * from `con_schöne_grüße`;
+exec $MYSQL_IMPORT test $MYSQLTEST_VARDIR/tmp/con@fame.txt;
+select * from `con_schöne_grüße`;
 select * from `con`;
 select * from `con/bar`;
-select * from `con@home`;
-drop table `con_schöne_grüße`;
+select * from `con@fame`;
+drop table `con_schöne_grüße`;
 drop table `con`;
 drop table `con/bar`;
-drop table `con@home`;
+drop table `con@fame`;
 
 --echo # End of 10.6 tests