Change of internal key_field=NULL handling to avoid error messages.

Optimized SELECT DISTINCT ... ORDER BY ... LIMIT
Fixed reference to uninitalized variable


mysql-test/r/distinct.result:
  Updated results for new tests
mysql-test/r/func_math.result:
  Fixed test of RND()
mysql-test/r/innodb.result:
  Updated results for new tests
mysql-test/r/null.result:
  Updated results for new tests
mysql-test/t/distinct.test:
  New distinct test
mysql-test/t/func_math.test:
  Fixed test of RND()
mysql-test/t/innodb.test:
  Test for bugs
mysql-test/t/null.test:
  TEst for bugs
sql/field.h:
  Change of NULL handling to avoid error messages
sql/field_conv.cc:
  Change of NULL handling to avoid error messages
sql/item.cc:
  Change of NULL handling to avoid error messages
sql/item.h:
  Change of NULL handling to avoid error messages
sql/item_cmpfunc.cc:
  Change of NULL handling to avoid error messages
sql/item_func.cc:
  Change of NULL handling to avoid error messages
sql/item_func.h:
  Cleaned up RND() handling
sql/item_timefunc.cc:
  Change of NULL handling to avoid error messages
sql/item_timefunc.h:
  Change of NULL handling to avoid error messages
sql/opt_range.cc:
  Fixed bug in <=> NULL
sql/password.c:
  Indentation cleanup
sql/sql_base.cc:
  Change of NULL handling to avoid error messages
sql/sql_class.cc:
  Fixed reference to uninitalized variable
sql/sql_handler.cc:
  Change of NULL handling to avoid error messages
sql/sql_select.cc:
  Change of NULL handling to avoid error messages
  Optimized SELECT DISTINCT ... ORDER BY ... LIMIT
sql/sql_select.h:
  Change of NULL handling to avoid error messages
sql/unireg.cc:
  Change of NULL handling to avoid error messages

1 files changed, 21 insertions, 3 deletions

diff --git a/sql/field_conv.cc b/sql/field_conv.cc
index 53b26920c14..ffc93f3e871 100644
--- a/sql/field_conv.cc
+++ b/sql/field_conv.cc
@@ -122,8 +122,26 @@ set_field_to_null(Field *field)
 }
 
 
+/*
+  Set field to NULL or TIMESTAMP or to next auto_increment number
+
+  SYNOPSIS
+    set_field_to_null_with_conversions()
+    field		Field to update
+    no_conversion	Set to 1 if we should return 1 if field can't
+			take null values.
+			If set to 0 we will do store the 'default value'
+			if the field is a special field. If not we will
+			give an error.
+
+  RETURN VALUES
+    0		Field could take 0 or an automatic conversion was used
+    1		Field could not take NULL and no conversion was used.
+		If no_conversion was not set, an error message is printed
+*/
+
 bool
-set_field_to_null_with_conversions(Field *field)
+set_field_to_null_with_conversions(Field *field, bool no_conversions)
 {
   if (field->real_maybe_null())
   {
@@ -131,6 +149,8 @@ set_field_to_null_with_conversions(Field *field)
     field->reset();
     return 0;
   }
+  if (no_conversions)
+    return 1;
 
   /*
     Check if this is a special type, which will get a special walue
@@ -156,8 +176,6 @@ set_field_to_null_with_conversions(Field *field)
 }
 
 
-
-
 static void do_skip(Copy_field *copy __attribute__((unused)))
 {
 }