Merge pilot.blaudden:/home/msvensson/mysql/mysql-5.0

into  pilot.blaudden:/home/msvensson/mysql/mysql-5.0-maint


client/mysql.cc:
  Auto merged
sql/item_cmpfunc.cc:
  Auto merged
sql/mysql_priv.h:
  Auto merged
sql/mysqld.cc:
  Auto merged

1 files changed, 14 insertions, 4 deletions

diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index 6f207e920d0..bf9ddcc6659 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -812,8 +812,18 @@ int Arg_comparator::compare_row()
     if (owner->null_value)
     {
       // NULL was compared
-      if (owner->abort_on_null)
-        return -1; // We do not need correct NULL returning
+      switch (owner->functype()) {
+      case Item_func::NE_FUNC:
+        break; // NE never aborts on NULL even if abort_on_null is set
+      case Item_func::LT_FUNC:
+      case Item_func::LE_FUNC:
+      case Item_func::GT_FUNC:
+      case Item_func::GE_FUNC:
+        return -1; // <, <=, > and >= always fail on NULL
+      default: // EQ_FUNC
+        if (owner->abort_on_null)
+          return -1; // We do not need correct NULL returning
+      }
       was_null= 1;
       owner->null_value= 0;
       res= 0;  // continue comparison (maybe we will meet explicit difference)
@@ -824,8 +834,8 @@ int Arg_comparator::compare_row()
   if (was_null)
   {
     /*
-      There was NULL(s) in comparison in some parts, but there was not
-      explicit difference in other parts, so we have to return NULL
+      There was NULL(s) in comparison in some parts, but there was no
+      explicit difference in other parts, so we have to return NULL.
     */
     owner->null_value= 1;
     return -1;