BUG#670417: Diverging results in maria-5.3-mwl128-dsmrr-cpk with join buffer

Switch from "Disable identical key handling optimization when
  IndexConditionPushdown is used" approach
To 
 an approach where we save/restore index tuple and so can use index condition pushdown.

1 files changed, 4 insertions, 7 deletions

diff --git a/sql/multi_range_read.h b/sql/multi_range_read.h
index 1851dc4912f..df6fc73ab52 100644
--- a/sql/multi_range_read.h
+++ b/sql/multi_range_read.h
@@ -271,7 +271,8 @@ public:
             mrr_funcs.skip_index_tuple(mrr_iter, range_info));
   }
 
-  void set_temp_space(uchar *space);
+  bool set_temp_space(uint rowid_length, uint key_len,
+                      uchar **space_start, uchar *space_end);
   void interrupt_read();
   void resume_read();
   void position();
@@ -291,12 +292,6 @@ private:
   /* TRUE <=> need range association, buffers hold {rowid, range_id} pairs */
   bool is_mrr_assoc;
   
-  /*
-    TRUE <=> Don't do optimizations for identical key value (see comment in
-    Mrr_ordered_index_reader::init for details)
-  */
-  bool disallow_identical_key_handling;
-  
   /* Range sequence iteration members */
   RANGE_SEQ_IF mrr_funcs;
   range_seq_t mrr_iter;
@@ -315,6 +310,8 @@ private:
   /* TRUE <=> saved_rowid has the last saved rowid */
   bool have_saved_rowid;
 
+  uchar *saved_key_tuple;
+
   static int compare_keys(void* arg, uchar* key1, uchar* key2);
   static int compare_keys_reverse(void* arg, uchar* key1, uchar* key2);