Bug#18053 Partitions: crash if null

Bug#18070 Partitions: wrong result on WHERE ... IS NULL
 removed unnecessary code
 added handling of NULL values

3 files changed, 22 insertions, 4 deletions

diff --git a/sql/opt_range.cc b/sql/opt_range.cc
index e9ebd9cbccb..36de27ef3e3 100644
--- a/sql/opt_range.cc
+++ b/sql/opt_range.cc
@@ -2296,6 +2296,7 @@ bool prune_partitions(THD *thd, TABLE *table, Item *pprune_cond)
   RANGE_OPT_PARAM  *range_par= &prune_param.range_param;
 
   prune_param.part_info= part_info;
+  prune_param.part_iter.has_null_value= FALSE;
 
   init_sql_alloc(&alloc, thd->variables.range_alloc_block_size, 0);
   range_par->mem_root= &alloc;
diff --git a/sql/sql_partition.cc b/sql/sql_partition.cc
index 682c74dc31e..d8a886d2227 100644
--- a/sql/sql_partition.cc
+++ b/sql/sql_partition.cc
@@ -2868,9 +2868,6 @@ uint32 get_partition_id_range_for_endpoint(partition_info *part_info,
   /* Get the partitioning function value for the endpoint */
   longlong part_func_value= part_val_int(part_info->part_expr);
 
-  if (part_info->part_expr->null_value)
-    DBUG_RETURN(0);
-
   while (max_part_id > min_part_id)
   {
     loc_part_id= (max_part_id + min_part_id + 1) >> 1;
@@ -5745,6 +5742,19 @@ int get_part_iter_for_interval_via_mapping(partition_info *part_info,
   else
     DBUG_ASSERT(0);
 
+  if (field->real_maybe_null() && part_info->has_null_value)
+  {
+    if (*min_value)
+    {
+      if (*max_value && !(flags & (NO_MIN_RANGE | NO_MAX_RANGE)))
+      {
+        init_single_partition_iterator(part_info->has_null_part_id, part_iter);
+        return 1;
+      }
+      if (!(flags & NEAR_MIN))
+        part_iter->has_null_value= TRUE;
+    }
+  }
   /* Find minimum */
   if (flags & NO_MIN_RANGE)
     part_iter->part_nums.start= 0;
@@ -5956,7 +5966,14 @@ uint32 get_next_partition_id_range(PARTITION_ITERATOR* part_iter)
 uint32 get_next_partition_id_list(PARTITION_ITERATOR *part_iter)
 {
   if (part_iter->part_nums.start == part_iter->part_nums.end)
+  {
+    if (part_iter->has_null_value)
+    {
+      part_iter->has_null_value= FALSE;
+      return part_iter->part_info->has_null_part_id;
+    }
     return NOT_A_PARTITION_ID;
+  }
   else
     return part_iter->part_info->list_array[part_iter->
                                             part_nums.start++].partition_id;
diff --git a/sql/sql_partition.h b/sql/sql_partition.h
index 4982b1fcf1f..c214be81ae4 100644
--- a/sql/sql_partition.h
+++ b/sql/sql_partition.h
@@ -124,7 +124,7 @@ typedef uint32 (*partition_iter_func)(st_partition_iter* part_iter);
 typedef struct st_partition_iter
 {
   partition_iter_func get_next;
-  
+  bool has_null_value;
   struct st_part_num_range
   {
     uint32 start;