bzr push into mysql-trunk branch (Dmitry.Shulga:4192 to 4193) WL#6030

[Dmitry Shulga]

 4193 Dmitry Shulga	2012-08-10
      The follow-up for WL#6030.
      
      Added some doxygen-style comments.

    modified:
      sql/field.cc
      sql/field.h
      sql/sql_base.cc
 4192 Dmitry Shulga	2012-08-08
      This is core patch for WL#6030.
      
      This patch does the following things:
       - changes Field class so that it is possible to set NOT NULL fields
      temporary to NULL;
      - allows NOT NULL fields to accept NULL values temporarily during
      BEFORE-trigger processing;
      - checks that the NOT NULL constraint is enforced after
      BEFORE-trigger processing.

    modified:
      mysql-test/r/warnings.result
      mysql-test/suite/funcs_1/r/innodb_trig_09.result
      mysql-test/suite/funcs_1/r/memory_trig_09.result
      mysql-test/suite/funcs_1/r/myisam_trig_09.result
      sql/field.cc
      sql/field.h
      sql/field_conv.cc
      sql/item.cc
      sql/item_sum.cc
      sql/sql_base.cc
=== modified file 'sql/field.cc'
--- a/sql/field.cc	2012-08-08 14:49:40 +0000
+++ b/sql/field.cc	2012-08-10 06:34:02 +0000
@@ -1425,6 +1425,12 @@ type_conversion_status Field::check_cons
 }
 
 
+/**
+  Set field to value NULL.
+
+  @param row_offset    This is the offset between the row being updated
+                       and table->record[0]
+*/
 void Field::set_null(my_ptrdiff_t row_offset)
 {
   if (real_maybe_null())
@@ -1439,6 +1445,12 @@ void Field::set_null(my_ptrdiff_t row_of
 }
 
 
+/**
+  Set field to value NOT NULL.
+
+  @param row_offset    This is the offset between the row being updated
+                       and table->record[0]
+*/
 void Field::set_notnull(my_ptrdiff_t row_offset)
 {
   if (real_maybe_null())

=== modified file 'sql/field.h'
--- a/sql/field.h	2012-08-08 14:49:40 +0000
+++ b/sql/field.h	2012-08-10 06:34:02 +0000
@@ -572,12 +572,31 @@ public:
         const char *field_name_arg);
   virtual ~Field() {}
 
+  /**
+    Turn on/off temporary nullability for the field.
+
+    @param is_tmp_nullable    NULLability flag:
+                                  true - turn on temporary NULLability
+                                  false - turn off temporary NULLability
+  */
   void set_tmp_nullable(bool is_tmp_nullable)
   { m_is_tmp_nullable= is_tmp_nullable; }
 
+  /**
+    Return temporary NULLability flag.
+
+    @return    true - if NULL can be assigned temporary to the Field
+               false - if NULL can not be assigned temporary to the Field
+  */
   bool is_tmp_nullable() const
   { return m_is_tmp_nullable; }
 
+  /**
+    Check whether Field has temporary value NULL.
+
+    @return    true - if the Field has temporary value NULL
+               false - if the Field's value is NOT NULL
+  */
   bool is_tmp_null() const
   { return is_tmp_nullable() && m_is_tmp_null; }
 
@@ -899,6 +918,12 @@ public:
   bool is_temporal_with_date_and_time() const
   { return is_temporal_type_with_date_and_time(type()); }
 
+  /**
+    Check whether the full table's row is NULL or the Field has value NULL.
+
+    @return    true if the full table's row is NULL or the Field has value NULL
+               false if neither table's row nor the Field has value NULL
+  */
   bool is_null(my_ptrdiff_t row_offset= 0) const
   {
     /*
@@ -918,6 +943,12 @@ public:
            is_real_null(row_offset);
   }
 
+  /**
+    Check whether the Field has value NULL (temporary or actual).
+
+    @return   true if the Field has value NULL (temporary or actual)
+              false if the Field has value NOT NULL.
+  */
   bool is_real_null(my_ptrdiff_t row_offset= 0) const
   {
     if (real_maybe_null())
@@ -929,6 +960,13 @@ public:
     return false;
   }
 
+  /**
+    Check if the Field has value NULL or the record specified by argument
+    has value NULL for this Field.
+
+    @return    true if the Field has value NULL or the record has value NULL
+               for thois Field.
+  */
   bool is_null_in_record(const uchar *record) const
   {
     if (real_maybe_null())
@@ -946,6 +984,13 @@ public:
 
   type_conversion_status check_constraints() const;
 
+  /**
+    Remember the value of THD::count_cuted_fields to handle possible
+    NOT-NULL constraint errors after BEFORE-trigger execution is finished.
+    We should save the value of THD::count_cuted_fields before starting
+    BEFORE-trigger processing since during triggers execution the
+    value of THD::count_cuted_fields could be changed.
+  */
   void set_count_cuted_fields(enum_check_fields count_cuted_fields)
   { m_count_cuted_fields_saved= count_cuted_fields; }
 

=== modified file 'sql/sql_base.cc'
--- a/sql/sql_base.cc	2012-08-08 14:49:40 +0000
+++ b/sql/sql_base.cc	2012-08-10 06:34:02 +0000
@@ -8979,6 +8979,11 @@ fill_record_n_invoke_before_triggers(THD
       Item_field *item_field= item->field_for_view_update();
       if (!item_field)
       {
+        /**
+          Rewind iterator for table's fields, iterate along
+          all fields and reset temporary NULLability flag for
+          every fields before this one that fired an error.
+        */
         it.rewind();
         Item *item_to_restore;
         while ((item_to_restore= it++) && item_to_restore != item)

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