Bug#25779239 ALTER TABLE FAILS WHEN DEFAULT CHARACTER SET CHANGES TO …

…UTF8MB4 Change-Id: Idc375b71b86f37daeff44424de635095c3d04c86 Problem: wrong calculation of column_length in prepare_key_column() Fix: multiply charset->mbmaxlen only for relevant field types.
mysql · Mar 27, 2017 · 8afbe2f · 8afbe2f
1 parent 2780e2a
commit 8afbe2f
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diff --git a/mysql-test/r/alter_table.result b/mysql-test/r/alter_table.result
@@ -3138,3 +3138,21 @@ FROM information_schema.triggers WHERE event_object_schema = 'test';
 TRIGGER_NAME	EVENT_OBJECT_SCHEMA	EVENT_OBJECT_TABLE	ACTION_STATEMENT
 t1_bi	test	t4	SET @a:=0
 DROP TABLE t4;
+
+Bug#25779239 ALTER TABLE FAILS WHEN DEFAULT
+CHARACTER SET CHANGES TO UTF8MB4
+
+CREATE TABLE t1(
+i INT UNSIGNED AUTO_INCREMENT NOT NULL PRIMARY KEY) charset latin1;
+ALTER TABLE t1
+DROP i,
+ADD i INT UNSIGNED NOT NULL AUTO_INCREMENT,
+AUTO_INCREMENT = 1;
+DROP TABLE t1;
+CREATE TABLE t1(
+i INT UNSIGNED AUTO_INCREMENT NOT NULL PRIMARY KEY) charset utf8mb4;
+ALTER TABLE t1
+DROP i,
+ADD i INT UNSIGNED NOT NULL AUTO_INCREMENT,
+AUTO_INCREMENT = 1;
+DROP TABLE t1;
diff --git a/mysql-test/t/alter_table.test b/mysql-test/t/alter_table.test
@@ -2587,3 +2587,24 @@ DROP TABLE t4;
 --eval alter schema test default character set $testdbcs108;
 --enable_query_log
 ########################################
+
+--echo
+--echo Bug#25779239 ALTER TABLE FAILS WHEN DEFAULT
+--echo              CHARACTER SET CHANGES TO UTF8MB4
+--echo
+
+CREATE TABLE t1(
+  i INT UNSIGNED AUTO_INCREMENT NOT NULL PRIMARY KEY) charset latin1;
+ALTER TABLE t1
+  DROP i,
+  ADD i INT UNSIGNED NOT NULL AUTO_INCREMENT,
+  AUTO_INCREMENT = 1;
+DROP TABLE t1;
+
+CREATE TABLE t1(
+  i INT UNSIGNED AUTO_INCREMENT NOT NULL PRIMARY KEY) charset utf8mb4;
+ALTER TABLE t1
+  DROP i,
+  ADD i INT UNSIGNED NOT NULL AUTO_INCREMENT,
+  AUTO_INCREMENT = 1;
+DROP TABLE t1;
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
@@ -5751,7 +5751,23 @@ static bool prepare_key_column(THD *thd, HA_CREATE_INFO *create_info,
   }
   else
   {
-    column_length= column->length * sql_field->charset->mbmaxlen;
+    switch (sql_field->sql_type) {
+    case MYSQL_TYPE_TINY_BLOB:
+    case MYSQL_TYPE_MEDIUM_BLOB:
+    case MYSQL_TYPE_LONG_BLOB:
+    case MYSQL_TYPE_BLOB:
+    case MYSQL_TYPE_GEOMETRY:
+    case MYSQL_TYPE_JSON:
+    case MYSQL_TYPE_VAR_STRING:
+    case MYSQL_TYPE_STRING:
+    case MYSQL_TYPE_VARCHAR:
+    case MYSQL_TYPE_ENUM:
+    case MYSQL_TYPE_SET:
+      column_length= column->length * sql_field->charset->mbmaxlen;
+      break;
+    default:
+      column_length= column->length;
+    }
 
     if (key->type == KEYTYPE_SPATIAL)
     {