[1.9.x] Refs #25894 -- Fixed evaluation of zero-length slices of QuerySet.values() on Oracle.

Backport of ed1bcf0515 from master

django/db/backends/oracle/compiler.py

@@ -12,9 +12,6 @@ class SQLCompiler(compiler.SQLCompiler):
         If 'with_limits' is False, any limit/offset information is not
         included in the query.
         """
-        if with_limits and self.query.low_mark == self.query.high_mark:
-            return '', ()
-
         # The `do_offset` flag indicates whether we need to construct
         # the SQL needed to use limit/offset with Oracle.
         do_offset = with_limits and (self.query.high_mark is not None

django/db/models/sql/compiler.py

@@ -380,8 +380,6 @@ class SQLCompiler(object):
         refcounts_before = self.query.alias_refcount.copy()
         try:
             extra_select, order_by, group_by = self.pre_sql_setup()
-            if with_limits and self.query.low_mark == self.query.high_mark:
-                return '', ()
             distinct_fields = self.get_distinct()
 
             # This must come after 'select', 'ordering', and 'distinct' -- see

django/db/models/sql/query.py

@@ -1565,6 +1565,9 @@ class Query(object):
             else:
                 self.low_mark = self.low_mark + low
 
+        if self.low_mark == self.high_mark:
+            self.set_empty()
+
     def clear_limits(self):
         """
         Clears any existing limits.