Bug #21180: Subselect with index for both WHERE and ORDER BY produces empty result

 Reseting subqueries with "quick" access methods was incomplete.
 Partially backported the correct reseting of QUICK_SELECTs from 5.x.


mysql-test/r/subselect.result:
  Bug #21180: Subselect with index for both WHERE and ORDER BY produces empty result
   - test case
mysql-test/t/subselect.test:
  Bug #21180: Subselect with index for both WHERE and ORDER BY produces empty result
   - test case
sql/opt_range.cc:
  Bug #21180: Subselect with index for both WHERE and ORDER BY produces empty result
   - partially backported the correct reseting of QUICK_SELECTs from 5.x.
sql/opt_range.h:
  Bug #21180: Subselect with index for both WHERE and ORDER BY produces empty result
   - partially backported the correct reseting of QUICK_SELECTs from 5.x.

1 files changed, 13 insertions, 1 deletions

diff --git a/sql/opt_range.cc b/sql/opt_range.cc
index 57903ffe7b9..85125a4521a 100644
--- a/sql/opt_range.cc
+++ b/sql/opt_range.cc
@@ -2980,6 +2980,14 @@ int QUICK_SELECT::get_next()
   }
 }
 
+void QUICK_SELECT::reset(void) 
+{
+  next= 0; 
+  it.rewind();
+  range= 0; 
+  if (file->inited == handler::NONE) 
+    file->ha_index_init(index);
+}
 
 /* Get next for geometrical indexes */
 
@@ -3201,7 +3209,11 @@ bool QUICK_SELECT_DESC::test_if_null_range(QUICK_RANGE *range_arg,
   return 0;
 }
 #endif
-
+void QUICK_SELECT_DESC::reset(void)
+{ 
+  rev_it.rewind();
+  QUICK_SELECT::reset();
+}
 
 /*****************************************************************************
 ** Print a quick range for debugging