Fixed a wrong merge in prune_partitions()

Added forgotten partition_explicit_prune from mysql-5.6.

Backported the fix for
Bug#13559657: PARTITION SELECTION DOES NOT WORK WITH VIEWS
from mysql-5.6

sql/opt_range.cc

@@ -3969,7 +3969,6 @@ end:
   thd->no_errors=0;
   thd->mem_root= range_par->old_root;
   free_root(&alloc,MYF(0));			// Return memory & allocator
-  DBUG_RETURN(retval);
   /*
     Must be a subset of the locked partitions.
     lock_partitions contains the partitions marked by explicit partition
@@ -3993,7 +3992,11 @@ end:
                 &prune_param.part_info->read_partitions);
   }
   if (bitmap_is_clear_all(&(prune_param.part_info->read_partitions)))
+  {
     table->all_partitions_pruned_away= true;
+    retval= TRUE;
+  }
+  DBUG_RETURN(retval);
 }
 
 

sql/sql_select.cc

@@ -23161,6 +23161,22 @@ void TABLE_LIST::print(THD *thd, table_map eliminated_tables, String *str,
         append_identifier(thd, str, table_name, table_name_length);
         cmp_name= table_name;
       }
+#ifdef WITH_PARTITION_STORAGE_ENGINE
+      if (partition_names && partition_names->elements)
+      {
+        int i, num_parts= partition_names->elements;
+        List_iterator<String> name_it(*(partition_names));
+        str->append(STRING_WITH_LEN(" PARTITION ("));
+        for (i= 1; i <= num_parts; i++)
+        {
+          String *name= name_it++;
+          append_identifier(thd, str, name->c_ptr(), name->length());
+          if (i != num_parts)
+            str->append(',');
+        }
+        str->append(')');
+      }
+#endif /* WITH_PARTITION_STORAGE_ENGINE */
     }
     if (my_strcasecmp(table_alias_charset, cmp_name, alias))
     {