Merging upstream version 1:11.4.2.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 24 insertions, 2 deletions

diff --git a/sql/sql_connect.cc b/sql/sql_connect.cc
index 6149cc49..f06a58a4 100644
--- a/sql/sql_connect.cc
+++ b/sql/sql_connect.cc
@@ -779,6 +779,10 @@ void update_global_user_stats(THD *thd, bool create_user, time_t now)
 bool thd_init_client_charset(THD *thd, uint cs_number)
 {
   CHARSET_INFO *cs;
+
+  // Test a non-default collation ID. See also comments in this function below.
+  DBUG_EXECUTE_IF("thd_init_client_charset_utf8mb3_bin", cs_number= 83;);
+
   /*
    Use server character set and collation if
    - opt_character_set_client_handshake is not set
@@ -801,6 +805,25 @@ bool thd_init_client_charset(THD *thd, uint cs_number)
                cs->cs_name.str);
       return true;
     }
+    /*
+      Some connectors (e.g. JDBC, Node.js) can send non-default collation IDs
+      in the handshake packet, to set @@collation_connection right during
+      handshake. Although this is a non-documenting feature,
+      for better backward compatibility with such connectors let's:
+      a. resolve only default collations according to @@character_set_collations
+      b. preserve non-default collations as is
+
+      Perhaps eventually we should change (b) also to resolve non-default
+      collations accoding to @@character_set_collations. Clients that used to
+      send a non-default collation ID in the handshake packet will have to set
+      @@character_set_collations instead.
+    */
+    if (cs->state & MY_CS_PRIMARY)
+    {
+      Sql_used used;
+      cs= global_system_variables.character_set_collations.
+            get_collation_for_charset(&used, cs);
+    }
     thd->org_charset= cs;
     thd->update_charset(cs,cs,cs);
   }
@@ -1077,7 +1100,6 @@ static int check_connection(THD *thd)
     statistic_increment(aborted_connects_preauth, &LOCK_status);
     return 1; /* The error is set by alloc(). */
   }
-
   auth_rc= acl_authenticate(thd, 0);
   if (auth_rc == 0 && connect_errors != 0)
   {
@@ -1132,7 +1154,7 @@ void setup_connection_thread_globals(THD *thd)
     1    error
 */
 
-bool login_connection(THD *thd)
+static bool login_connection(THD *thd)
 {
   NET *net= &thd->net;
   int error= 0;