Fix of LP BUG#780386.

ALL subquery should return TRUE if subquery rowa set is empty independently
of left part.  The problem was that Item_func_(eq,ne,gt,ge,lt,le) do not
call execution of second argument if first is NULL no in this case subquery
will not be executed and when Item_func_not_all calls any_value() of the
subquery or aggregation function which report that there was rows. So for
NULL < ALL (SELECT...) result was FALSE instead of TRUE.

Fix is just swapping of arguments of Item_func_(eq,ne,gt,ge,lt,le) (with
changing the operation if it is needed) so that result will be the same
(for examole a < b is equal to b > a). This fix exploit the fact that
first argument will be executed in any case.

mysql-test/r/subselect.result:
  The test suite added.
mysql-test/r/subselect_no_mat.result:
  The test suite added.
mysql-test/r/subselect_no_opts.result:
  The test suite added.
mysql-test/r/subselect_no_semijoin.result:
  The test suite added.
mysql-test/r/subselect_scache.result:
  The test suite added.
mysql-test/t/subselect.test:
  The test suite added.
sql/item_cmpfunc.cc:
  Swap arguments creation methods added.
sql/item_cmpfunc.h:
  Swap arguments creation methods added.
sql/item_subselect.cc:
  Swap arguments of the comparison.

1 files changed, 13 insertions, 0 deletions

diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h
index 63d38c8e53e..02989b17f3c 100644
--- a/sql/item_cmpfunc.h
+++ b/sql/item_cmpfunc.h
@@ -267,7 +267,14 @@ class Comp_creator
 public:
   Comp_creator() {}                           /* Remove gcc warning */
   virtual ~Comp_creator() {}                  /* Remove gcc warning */
+  /**
+    Create operation with given arguments.
+  */
   virtual Item_bool_func2* create(Item *a, Item *b) const = 0;
+  /**
+    Create operation with given arguments in swap order.
+  */
+  virtual Item_bool_func2* create_swap(Item *a, Item *b) const = 0;
   virtual const char* symbol(bool invert) const = 0;
   virtual bool eqne_op() const = 0;
   virtual bool l_op() const = 0;
@@ -279,6 +286,7 @@ public:
   Eq_creator() {}                             /* Remove gcc warning */
   virtual ~Eq_creator() {}                    /* Remove gcc warning */
   virtual Item_bool_func2* create(Item *a, Item *b) const;
+  virtual Item_bool_func2* create_swap(Item *a, Item *b) const;
   virtual const char* symbol(bool invert) const { return invert? "<>" : "="; }
   virtual bool eqne_op() const { return 1; }
   virtual bool l_op() const { return 0; }
@@ -290,6 +298,7 @@ public:
   Ne_creator() {}                             /* Remove gcc warning */
   virtual ~Ne_creator() {}                    /* Remove gcc warning */
   virtual Item_bool_func2* create(Item *a, Item *b) const;
+  virtual Item_bool_func2* create_swap(Item *a, Item *b) const;
   virtual const char* symbol(bool invert) const { return invert? "=" : "<>"; }
   virtual bool eqne_op() const { return 1; }
   virtual bool l_op() const { return 0; }
@@ -301,6 +310,7 @@ public:
   Gt_creator() {}                             /* Remove gcc warning */
   virtual ~Gt_creator() {}                    /* Remove gcc warning */
   virtual Item_bool_func2* create(Item *a, Item *b) const;
+  virtual Item_bool_func2* create_swap(Item *a, Item *b) const;
   virtual const char* symbol(bool invert) const { return invert? "<=" : ">"; }
   virtual bool eqne_op() const { return 0; }
   virtual bool l_op() const { return 0; }
@@ -312,6 +322,7 @@ public:
   Lt_creator() {}                             /* Remove gcc warning */
   virtual ~Lt_creator() {}                    /* Remove gcc warning */
   virtual Item_bool_func2* create(Item *a, Item *b) const;
+  virtual Item_bool_func2* create_swap(Item *a, Item *b) const;
   virtual const char* symbol(bool invert) const { return invert? ">=" : "<"; }
   virtual bool eqne_op() const { return 0; }
   virtual bool l_op() const { return 1; }
@@ -323,6 +334,7 @@ public:
   Ge_creator() {}                             /* Remove gcc warning */
   virtual ~Ge_creator() {}                    /* Remove gcc warning */
   virtual Item_bool_func2* create(Item *a, Item *b) const;
+  virtual Item_bool_func2* create_swap(Item *a, Item *b) const;
   virtual const char* symbol(bool invert) const { return invert? "<" : ">="; }
   virtual bool eqne_op() const { return 0; }
   virtual bool l_op() const { return 0; }
@@ -334,6 +346,7 @@ public:
   Le_creator() {}                             /* Remove gcc warning */
   virtual ~Le_creator() {}                    /* Remove gcc warning */
   virtual Item_bool_func2* create(Item *a, Item *b) const;
+  virtual Item_bool_func2* create_swap(Item *a, Item *b) const;
   virtual const char* symbol(bool invert) const { return invert? ">" : "<="; }
   virtual bool eqne_op() const { return 0; }
   virtual bool l_op() const { return 1; }