MDEV-19750 mysql command wrong encoding

Restore the detection of default charset in command line utilities.
It worked up to 10.1, but was broken by Connector/C.

Moved code for detection of default charset from sql-common/client.c
to mysys, and make command line utilities to use this code if charset
was not specified on the command line.

5 files changed, 17 insertions, 5 deletions

diff --git a/client/mysql.cc b/client/mysql.cc
index 06bf31e16ce..2247e93ca93 100644
--- a/client/mysql.cc
+++ b/client/mysql.cc
@@ -40,6 +40,7 @@
 #include "my_readline.h"
 #include <signal.h>
 #include <violite.h>
+#include <my_sys.h>
 
 #if defined(USE_LIBEDIT_INTERFACE) && defined(HAVE_LOCALE_H)
 #include <locale.h>
@@ -4701,7 +4702,8 @@ sql_real_connect(char *host,char *database,char *user,char *password,
 	    select_limit,max_join_size);
     mysql_options(&mysql, MYSQL_INIT_COMMAND, init_command);
   }
-
+  if (!strcmp(default_charset,MYSQL_AUTODETECT_CHARSET_NAME))
+    default_charset= (char *)my_default_csname();
   mysql_options(&mysql, MYSQL_SET_CHARSET_NAME, default_charset);
 
   if (!do_connect(&mysql, host, user, password, database,
diff --git a/client/mysqladmin.cc b/client/mysqladmin.cc
index ef8cb27e672..a4e06b46d94 100644
--- a/client/mysqladmin.cc
+++ b/client/mysqladmin.cc
@@ -26,6 +26,7 @@
 #include <welcome_copyright_notice.h>
 #include <my_rnd.h>
 #include <password.h>
+#include <my_sys.h>
 
 #define ADMIN_VERSION "9.1"
 #define MAX_MYSQL_VAR 512
@@ -371,6 +372,8 @@ int main(int argc,char *argv[])
   if (shared_memory_base_name)
     mysql_options(&mysql,MYSQL_SHARED_MEMORY_BASE_NAME,shared_memory_base_name);
 #endif
+  if (!strcmp(default_charset,MYSQL_AUTODETECT_CHARSET_NAME))
+    default_charset= (char *)my_default_csname();
   mysql_options(&mysql, MYSQL_SET_CHARSET_NAME, default_charset);
   error_flags= (myf)(opt_nobeep ? 0 : ME_BELL);
 
diff --git a/client/mysqlcheck.c b/client/mysqlcheck.c
index ae8ddeec59c..42c4cae5621 100644
--- a/client/mysqlcheck.c
+++ b/client/mysqlcheck.c
@@ -440,8 +440,10 @@ static int get_options(int *argc, char ***argv)
     else
       default_charset= (char*) MYSQL_AUTODETECT_CHARSET_NAME;
   }
-  if (strcmp(default_charset, MYSQL_AUTODETECT_CHARSET_NAME) &&
-      !get_charset_by_csname(default_charset, MY_CS_PRIMARY, MYF(MY_WME)))
+  if (!strcmp(default_charset, MYSQL_AUTODETECT_CHARSET_NAME))
+    default_charset= (char *)my_default_csname();
+
+  if (!get_charset_by_csname(default_charset, MY_CS_PRIMARY, MYF(MY_WME)))
   {
     printf("Unsupported character set: %s\n", default_charset);
     DBUG_RETURN(1);
diff --git a/client/mysqlimport.c b/client/mysqlimport.c
index 722b23844d9..9d8239fe6db 100644
--- a/client/mysqlimport.c
+++ b/client/mysqlimport.c
@@ -30,6 +30,8 @@
 #define IMPORT_VERSION "3.7"
 
 #include "client_priv.h"
+#include <my_sys.h>
+
 #include "mysql_version.h"
 
 #include <welcome_copyright_notice.h>   /* ORACLE_WELCOME_COPYRIGHT_NOTICE */
@@ -472,8 +474,9 @@ static MYSQL *db_connect(char *host, char *database,
 
   if (opt_default_auth && *opt_default_auth)
     mysql_options(mysql, MYSQL_DEFAULT_AUTH, opt_default_auth);
-
-  mysql_options(mysql, MYSQL_SET_CHARSET_NAME, default_charset);
+  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_OPT_CONNECT_ATTR_RESET, 0);
   mysql_options4(mysql, MYSQL_OPT_CONNECT_ATTR_ADD,
                  "program_name", "mysqlimport");
diff --git a/client/mysqlshow.c b/client/mysqlshow.c
index 3fb2d371f2f..47dc7212ca2 100644
--- a/client/mysqlshow.c
+++ b/client/mysqlshow.c
@@ -135,6 +135,8 @@ int main(int argc, char **argv)
   if (shared_memory_base_name)
     mysql_options(&mysql,MYSQL_SHARED_MEMORY_BASE_NAME,shared_memory_base_name);
 #endif
+  if (!strcmp(default_charset,MYSQL_AUTODETECT_CHARSET_NAME))
+    default_charset= (char *)my_default_csname();
   mysql_options(&mysql, MYSQL_SET_CHARSET_NAME, default_charset);
 
   if (opt_plugin_dir && *opt_plugin_dir)