Bug#34463089 [InnoDB] Assertion failure:

 btr0cur.cc:4024:page_zip || optim_err != DB_UNDERFLO

Issue :
  When a column is being dropped from a table and in the same alter
  command if another existing column of table is being renamed to
  column being dropped, then physical positions of the columns are
  not set correctly.

Fix:
  Physical position of column never changes even if it is being
  renamed or dropped. So set the column physical position correctly.

Change-Id: I4bc387dd55330bcedfb4a26404a3d7dd9f58eb32

Author: mayprasa

storage/innobase/dict/dict0dd.cc

@@ -1664,9 +1664,9 @@ bool is_dropped(const Alter_inplace_info *ha_alter_info,
 
 void dd_copy_table_columns(const Alter_inplace_info *ha_alter_info,
                            dd::Table &new_table, const dd::Table &old_table,
-                           dict_table_t *dict_table) {
+                           dict_table_t *old_dict_table) {
   bool first_row_version = false;
-  if (dict_table && !dict_table->has_row_versions()) {
+  if (old_dict_table && !old_dict_table->has_row_versions()) {
     first_row_version = true;
   }
 
@@ -1684,13 +1684,11 @@ void dd_copy_table_columns(const Alter_inplace_info *ha_alter_info,
 
     dd::Column *new_col = nullptr;
     std::string new_name;
-    IF_DEBUG(bool renamed = false;)
 
     /* Skip the dropped column */
     if (is_dropped(ha_alter_info, old_col->name().c_str())) {
       continue;
     } else if (is_renamed(ha_alter_info, old_col->name().c_str(), new_name)) {
-      IF_DEBUG(renamed = true;)
       new_col = const_cast<dd::Column *>(
           dd_find_column(&new_table, new_name.c_str()));
     } else {
@@ -1708,14 +1706,11 @@ void dd_copy_table_columns(const Alter_inplace_info *ha_alter_info,
     }
 
     /* If this is first time table is getting row version, add physical pos */
-    if (dict_table && !new_col->is_virtual() && first_row_version) {
-      dict_col_t *col = dict_table->get_col_by_name(new_col->name().c_str());
-      if (col == nullptr) {
-        ut_ad(renamed);
-        col = dict_table->get_col_by_name(old_col->name().c_str());
-      }
-
-      ut_ad(col != nullptr);
+    if (old_dict_table && !new_col->is_virtual() && first_row_version) {
+      /* Even the renamed column would have same phy_pos as old column */
+      dict_col_t *col =
+          old_dict_table->get_col_by_name(old_col->name().c_str());
+      ut_a(col != nullptr);
       new_col->se_private_data().set(s, col->get_phy_pos());
     }
   }