MDEV-22506 Malformed error message for ER_KEY_CONTAINS_PERIOD_FIELDS

Though this is an error message task, the problem was deep in the
`mysql_prepare_create_table` implementation. The problem is described as
follows:

1. `append_system_key_parts` was called before
`mysql_prepare_create_table`, though key name generation was done close to
the latest stage of the latter.
2. We can't move `append_system_key_parts` in the end, because system keys
should be appended before some checks done.
3. If the checks from `append_system_key_parts` are moved to the end of
`mysql_prepare_create_table`, then some other inappropriate errors are
issued. like `ER_DUP_FIELDNAME`.

To have key name specified in error message, name generation should be done
before the checks, which consequenced in more changes.

The final design for key initialization in `mysql_prepare_create_table`
follows. The initialization is done in three phases:
1. Calculate a total number of keys created with respect to keys ignored.
 Allocate KEY* buffer.
2. Generate unique names; calculate a total number of key parts.
 Make early checks. Allocate KEY_PART_INFO* buffer.
3. Initialize key parts, make the rest of the checks.

1 files changed, 106 insertions, 88 deletions

diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 67a505d78bc..c2ba9bcadfb 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -75,9 +75,8 @@ static int copy_data_between_tables(THD *, TABLE *,TABLE *,
                                     ha_rows *, ha_rows *,
                                     Alter_info::enum_enable_or_disable,
                                     Alter_table_ctx *);
-static bool append_system_key_parts(THD *thd, HA_CREATE_INFO *create_info,
-                                    Alter_info *alter_info, KEY **key_info,
-                                    uint key_count);
+static int append_system_key_parts(THD *thd, HA_CREATE_INFO *create_info,
+                                   Key *key);
 static int mysql_prepare_create_table(THD *, HA_CREATE_INFO *, Alter_info *,
                                       uint *, handler *, KEY **, uint *, int);
 static uint blob_length_by_type(enum_field_types type);
@@ -1823,10 +1822,6 @@ bool mysql_write_frm(ALTER_PARTITION_PARAM_TYPE *lpt, uint flags)
   strxmov(shadow_frm_name, shadow_path, reg_ext, NullS);
   if (flags & WFRM_WRITE_SHADOW)
   {
-    if (append_system_key_parts(lpt->thd, lpt->create_info, lpt->alter_info,
-                                &lpt->key_info_buffer, 0))
-      DBUG_RETURN(true);
-
     if (mysql_prepare_create_table(lpt->thd, lpt->create_info, lpt->alter_info,
                                    &lpt->db_options, lpt->table->file,
                                    &lpt->key_info_buffer, &lpt->key_count,
@@ -3557,7 +3552,6 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,
   Create_field	*sql_field,*dup_field;
   uint		field,null_fields,max_key_length;
   ulong		record_offset= 0;
-  KEY		*key_info;
   KEY_PART_INFO *key_part_info;
   int		field_no,dup_no;
   int		select_field_pos,auto_increment=0;
@@ -3875,6 +3869,57 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,
       thd->abort_on_warning= sav_abort_on_warning;
     }
   }
+
+  KEY *key_info= *key_info_buffer= (KEY*)thd->calloc(sizeof(KEY) * (*key_count));
+  if (!*key_info_buffer)
+    DBUG_RETURN(true);				// Out of memory
+
+  key_iterator.rewind();
+  while ((key=key_iterator++))
+  {
+    if (key->name.str == ignore_key || key->type == Key::FOREIGN_KEY)
+      continue;
+    /* Create the key->ame based on the first column (if not given) */
+    if (key->type == Key::PRIMARY)
+    {
+      if (primary_key)
+      {
+        my_message(ER_MULTIPLE_PRI_KEY, ER_THD(thd, ER_MULTIPLE_PRI_KEY),
+                   MYF(0));
+        DBUG_RETURN(true);
+      }
+      key_name=primary_key_name;
+      primary_key=1;
+    }
+    else if (!(key_name= key->name.str))
+    {
+      auto field_name= key->columns.elem(0)->field_name;
+      it.rewind();
+      while ((sql_field=it++) &&
+             lex_string_cmp(system_charset_info,
+                            &field_name,
+                            &sql_field->field_name));
+      if (sql_field)
+        field_name= sql_field->field_name;
+      key_name=make_unique_key_name(thd, field_name.str,
+                                    *key_info_buffer, key_info);
+    }
+    if (check_if_keyname_exists(key_name, *key_info_buffer, key_info))
+    {
+      my_error(ER_DUP_KEYNAME, MYF(0), key_name);
+      DBUG_RETURN(true);
+    }
+
+    key_info->name.str= (char*) key_name;
+    key_info->name.length= strlen(key_name);
+    key->name= key_info->name;
+
+    int parts_added= append_system_key_parts(thd, create_info, key);
+    if (parts_added < 0)
+      DBUG_RETURN(true);
+    key_parts += parts_added;
+    key_info++;
+  }
   tmp=file->max_keys();
   if (*key_count > tmp)
   {
@@ -3882,11 +3927,11 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,
     DBUG_RETURN(TRUE);
   }
 
-  (*key_info_buffer)= key_info= (KEY*) thd->calloc(sizeof(KEY) * (*key_count));
   key_part_info=(KEY_PART_INFO*) thd->calloc(sizeof(KEY_PART_INFO)*key_parts);
-  if (!*key_info_buffer || ! key_part_info)
-    DBUG_RETURN(TRUE);				// Out of memory
+  if (!key_part_info)
+    DBUG_RETURN(true);				// Out of memory
 
+  key_info= *key_info_buffer;
   key_iterator.rewind();
   key_number=0;
   for (; (key=key_iterator++) ; key_number++)
@@ -4257,32 +4302,6 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,
 
       key_length+= key_part_length;
       key_part_info++;
-
-      /* Create the key name based on the first column (if not given) */
-      if (column_nr == 0)
-      {
-	if (key->type == Key::PRIMARY)
-	{
-	  if (primary_key)
-	  {
-	    my_message(ER_MULTIPLE_PRI_KEY, ER_THD(thd, ER_MULTIPLE_PRI_KEY),
-                       MYF(0));
-	    DBUG_RETURN(TRUE);
-	  }
-	  key_name=primary_key_name;
-	  primary_key=1;
-	}
-	else if (!(key_name= key->name.str))
-	  key_name=make_unique_key_name(thd, sql_field->field_name.str,
-					*key_info_buffer, key_info);
-	if (check_if_keyname_exists(key_name, *key_info_buffer, key_info))
-	{
-	  my_error(ER_DUP_KEYNAME, MYF(0), key_name);
-	  DBUG_RETURN(TRUE);
-	}
-	key_info->name.str= (char*) key_name;
-        key_info->name.length= strlen(key_name);
-      }
     }
     if (!key_info->name.str || check_column_name(key_info->name.str))
     {
@@ -4715,72 +4734,75 @@ bool Column_definition::sp_prepare_create_field(THD *thd, MEM_ROOT *mem_root)
 }
 
 
-static bool append_system_key_parts(THD *thd, HA_CREATE_INFO *create_info,
-                                    Alter_info *alter_info, KEY **key_info,
-                                    uint key_count)
+/**
+  Appends key parts generated by mariadb server.
+  Adds row_end in UNIQUE keys for system versioning,
+  and period fields for WITHOUT OVERLAPS.
+  @param thd Thread data
+  @param create_info Table create info
+  @param key Parsed key
+  @return a number of key parts added to key.
+ */
+static int append_system_key_parts(THD *thd, HA_CREATE_INFO *create_info,
+                                    Key *key)
 {
   const Lex_ident &row_start_field= create_info->vers_info.as_row.start;
   const Lex_ident &row_end_field= create_info->vers_info.as_row.end;
   DBUG_ASSERT(!create_info->versioned() || (row_start_field && row_end_field));
 
-  List_iterator<Key> key_it(alter_info->key_list);
-  Key *key= NULL;
-
-  if (create_info->versioned())
+  int result = 0;
+  if (create_info->versioned() && (key->type == Key::PRIMARY
+                                   || key->type == Key::UNIQUE))
   {
-    while ((key=key_it++))
+    Key_part_spec *key_part=NULL;
+    List_iterator<Key_part_spec> part_it(key->columns);
+    while ((key_part=part_it++))
     {
-      if (key->type != Key::PRIMARY && key->type != Key::UNIQUE)
-        continue;
-
-      Key_part_spec *key_part=NULL;
-      List_iterator<Key_part_spec> part_it(key->columns);
-      while ((key_part=part_it++))
-      {
-        if (row_start_field.streq(key_part->field_name) ||
-            row_end_field.streq(key_part->field_name))
-          break;
-      }
-      if (!key_part)
-        key->columns.push_back(new (thd->mem_root)
+      if (row_start_field.streq(key_part->field_name) ||
+          row_end_field.streq(key_part->field_name))
+        break;
+    }
+    if (!key_part)
+    {
+      key->columns.push_back(new (thd->mem_root)
                                Key_part_spec(&row_end_field, 0, true));
+      result++;
     }
-    key_it.rewind();
+
   }
 
-  while ((key=key_it++))
+  if (key->without_overlaps)
   {
-    if (key->without_overlaps)
+    DBUG_ASSERT(key->type == Key::PRIMARY || key->type == Key::UNIQUE);
+    if (!create_info->period_info.is_set()
+        || !key->period.streq(create_info->period_info.name))
     {
-      DBUG_ASSERT(key->type == Key::PRIMARY || key->type == Key::UNIQUE);
-      if (!create_info->period_info.is_set()
-          || !key->period.streq(create_info->period_info.name))
-      {
-        my_error(ER_PERIOD_NOT_FOUND, MYF(0), key->period.str);
-        return true;
-      }
+      my_error(ER_PERIOD_NOT_FOUND, MYF(0), key->period.str);
+      return -1;
+    }
 
-      const auto &period_start= create_info->period_info.period.start;
-      const auto &period_end= create_info->period_info.period.end;
-      List_iterator<Key_part_spec> part_it(key->columns);
-      while (Key_part_spec *key_part= part_it++)
+    const auto &period_start= create_info->period_info.period.start;
+    const auto &period_end= create_info->period_info.period.end;
+    List_iterator<Key_part_spec> part_it(key->columns);
+    while (Key_part_spec *key_part= part_it++)
+    {
+      if (period_start.streq(key_part->field_name)
+          || period_end.streq(key_part->field_name))
       {
-        if (period_start.streq(key_part->field_name)
-            || period_end.streq(key_part->field_name))
-        {
-          my_error(ER_KEY_CONTAINS_PERIOD_FIELDS, MYF(0), key->name.str,
-                   key_part->field_name);
-          return true;
-        }
+        my_error(ER_KEY_CONTAINS_PERIOD_FIELDS, MYF(0), key->name.str,
+                 key_part->field_name.str);
+        return -1;
       }
-      key->columns.push_back(new (thd->mem_root)
-                             Key_part_spec(&period_end, 0));
-      key->columns.push_back(new (thd->mem_root)
-                             Key_part_spec(&period_start, 0));
     }
+    const auto &period= create_info->period_info.period;
+    key->columns.push_back(new (thd->mem_root)
+                           Key_part_spec(&period.end, 0, true));
+    key->columns.push_back(new (thd->mem_root)
+                           Key_part_spec(&period.start, 0, true));
+    result += 2;
   }
 
-  return false;
+  return result;
 }
 
 handler *mysql_create_frm_image(THD *thd, const LEX_CSTRING &db,
@@ -5018,10 +5040,6 @@ handler *mysql_create_frm_image(THD *thd, const LEX_CSTRING &db,
   }
 #endif
 
-  if (append_system_key_parts(thd, create_info, alter_info, key_info,
-                              *key_count))
-    goto err;
-
   if (mysql_prepare_create_table(thd, create_info, alter_info, &db_options,
                                  file, key_info, key_count, create_table_mode))
     goto err;