From 1668efb722d6d2fb483745d23915378167937d1d Mon Sep 17 00:00:00 2001
From: Aleksey Midenkov <midenok@gmail.com>
Date: Thu, 14 Dec 2017 18:14:21 +0300
Subject: MDEV-14645: AS OF TIMESTAMP is misused as TRX_ID [fixes #396]

---
 sql/item_func.h      | 24 ++++++++++++++++++++++++
 sql/item_timefunc.cc | 20 ++++++++++++++++++++
 sql/item_timefunc.h  | 14 ++++++++++++++
 sql/sql_select.cc    | 42 ++++++++++++++++++++++++++++++++++++++++++
 sql/sql_type.cc      |  8 ++++++++
 sql/sql_type.h       |  3 +++
 6 files changed, 111 insertions(+)

(limited to 'sql')

diff --git a/sql/item_func.h b/sql/item_func.h
index f6640c9b719..4c78edcb1fa 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -988,6 +988,30 @@ public:
 };
 
 
+class Item_longlong_typecast :public Item_int_func
+{
+public:
+  Item_longlong_typecast(THD *thd, Item *a): Item_int_func(thd, a)
+  {
+  }
+  const char *func_name() const { return "cast_as_longlong"; }
+  const char *cast_type() const { return "longlong"; }
+  const Type_handler *type_handler() const { return &type_handler_longlong; }
+  longlong val_int()
+  {
+    return args[0]->val_int();
+  }
+  void fix_length_and_dec_generic() {}
+  void fix_length_and_dec()
+  {
+    args[0]->type_handler()->Item_longlong_typecast_fix_length_and_dec(this);
+  }
+  bool need_parentheses_in_default() { return true; }
+  Item *get_copy(THD *thd)
+  { return get_item_copy<Item_longlong_typecast>(thd, this); }
+};
+
+
 
 class Item_func_additive_op :public Item_num_op
 {
diff --git a/sql/item_timefunc.cc b/sql/item_timefunc.cc
index fd170a707c9..4563f4555f5 100644
--- a/sql/item_timefunc.cc
+++ b/sql/item_timefunc.cc
@@ -2652,6 +2652,26 @@ bool Item_datetime_typecast::get_date(MYSQL_TIME *ltime, ulonglong fuzzy_date)
 }
 
 
+void Item_datetime_from_unixtime_typecast::fix_length_and_dec()
+{
+  Item_datetime_typecast::fix_length_and_dec();
+
+  switch (args[0]->result_type())
+  {
+  case INT_RESULT:
+  case REAL_RESULT:
+  case DECIMAL_RESULT:
+  {
+    Item_func_from_unixtime *a= new (thd->mem_root) Item_func_from_unixtime(thd, args[0]);
+    a->fix_length_and_dec();
+    args[0]= a;
+    break;
+  }
+  default:;
+  }
+}
+
+
 /**
   MAKEDATE(a,b) is a date function that creates a date value 
   from a year and day value.
diff --git a/sql/item_timefunc.h b/sql/item_timefunc.h
index adc7b2535a9..878179105be 100644
--- a/sql/item_timefunc.h
+++ b/sql/item_timefunc.h
@@ -1184,6 +1184,20 @@ public:
 };
 
 
+class Item_datetime_from_unixtime_typecast :public Item_datetime_typecast
+{
+  THD *thd;
+public:
+  Item_datetime_from_unixtime_typecast(THD *_thd, Item *a, uint dec_arg):
+    Item_datetime_typecast(_thd, a, dec_arg), thd(_thd) {}
+  const char *func_name() const { return "cast_as_datetime_from_unixtime"; }
+  const char *cast_type() const { return "datetime"; }
+  void fix_length_and_dec();
+  Item *get_copy(THD *thd)
+  { return get_item_copy<Item_datetime_from_unixtime_typecast>(thd, this); }
+};
+
+
 class Item_func_makedate :public Item_datefunc
 {
   bool check_arguments() const
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index cd6c7877354..dca4b60dc4d 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -912,6 +912,48 @@ int SELECT_LEX::vers_setup_conds(THD *thd, TABLE_LIST *tables, COND **where_expr
     if (tmp_from_ib || t->versioned_by_sql() ||
         thd->variables.vers_innodb_algorithm_simple)
     {
+      if (vers_conditions)
+      {
+        if (vers_conditions.start)
+        {
+          switch (vers_conditions.unit_start)
+          {
+          case UNIT_TIMESTAMP:
+          {
+            vers_conditions.start= newx Item_datetime_from_unixtime_typecast(
+              thd, vers_conditions.start, 6);
+            break;
+          }
+          case UNIT_TRX_ID:
+          {
+            vers_conditions.start= newx Item_longlong_typecast(
+              thd, vers_conditions.start);
+            break;
+          }
+          default:;
+          }
+        }
+
+        if (vers_conditions.end)
+        {
+          switch (vers_conditions.unit_end)
+          {
+          case UNIT_TIMESTAMP:
+          {
+            vers_conditions.end= newx Item_datetime_from_unixtime_typecast(
+              thd, vers_conditions.end, 6);
+            break;
+          }
+          case UNIT_TRX_ID:
+          {
+            vers_conditions.end= newx Item_longlong_typecast(
+              thd, vers_conditions.end);
+            break;
+          }
+          default:;
+          }
+        }
+      }
       switch (vers_conditions.type)
       {
       case FOR_SYSTEM_TIME_UNSPECIFIED:
diff --git a/sql/sql_type.cc b/sql/sql_type.cc
index b4860176c0c..e1fb9cb51a0 100644
--- a/sql/sql_type.cc
+++ b/sql/sql_type.cc
@@ -4447,6 +4447,14 @@ bool Type_handler::
 }
 
 
+bool Type_handler::
+       Item_longlong_typecast_fix_length_and_dec(Item_longlong_typecast *item) const
+{
+  item->fix_length_and_dec_generic();
+  return false;
+}
+
+
 #ifdef HAVE_SPATIAL
 
 bool Type_handler_geometry::
diff --git a/sql/sql_type.h b/sql/sql_type.h
index c400420586e..ac95c5a9c88 100644
--- a/sql/sql_type.h
+++ b/sql/sql_type.h
@@ -55,6 +55,7 @@ class Item_char_typecast;
 class Item_time_typecast;
 class Item_date_typecast;
 class Item_datetime_typecast;
+class Item_longlong_typecast;
 class Item_func_plus;
 class Item_func_minus;
 class Item_func_mul;
@@ -983,6 +984,8 @@ public:
   Item_date_typecast_fix_length_and_dec(Item_date_typecast *item) const;
   virtual bool
   Item_datetime_typecast_fix_length_and_dec(Item_datetime_typecast *item) const;
+  virtual bool
+  Item_longlong_typecast_fix_length_and_dec(Item_longlong_typecast *item) const;
 
   virtual bool
   Item_func_plus_fix_length_and_dec(Item_func_plus *func) const= 0;
-- 
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