- Fixed bug where the combination of "limit" rendering askonsta_3022

"SELECT FIRST n ROWS" using a bound parameter (only firebird has both),
combined with column-level subqueries
which also feature "limit" as well as "positional" bound parameters
(e.g. qmark style) would erroneously assign the subquery-level positions
before that of the enclosing SELECT, thus returning parameters which
are out of order. Fixes #3038

2 files changed, 34 insertions, 2 deletions

diff --git a/test/dialect/test_firebird.py b/test/dialect/test_firebird.py
index 222e34b93..86464c8cb 100644
--- a/test/dialect/test_firebird.py
+++ b/test/dialect/test_firebird.py
@@ -415,8 +415,8 @@ class MiscTest(fixtures.TestBase):
     @testing.provide_metadata
     def test_rowcount_flag(self):
         metadata = self.metadata
-        engine = engines.testing_engine(options={'enable_rowcount'
-                : True})
+        engine = engines.testing_engine(
+                        options={'enable_rowcount': True})
         assert engine.dialect.supports_sane_rowcount
         metadata.bind = engine
         t = Table('t1', metadata, Column('data', String(10)))
@@ -431,6 +431,7 @@ class MiscTest(fixtures.TestBase):
         r = \
             t.delete().execution_options(enable_rowcount=False).execute()
         eq_(r.rowcount, -1)
+        engine.dispose()
         engine = engines.testing_engine(options={'enable_rowcount'
                 : False})
         assert not engine.dialect.supports_sane_rowcount
@@ -444,6 +445,8 @@ class MiscTest(fixtures.TestBase):
         eq_(r.rowcount, -1)
         r = t.delete().execution_options(enable_rowcount=True).execute()
         eq_(r.rowcount, 1)
+        r.close()
+        engine.dispose()
 
     def test_percents_in_text(self):
         for expr, result in (text("select '%' from rdb$database"), '%'
diff --git a/test/sql/test_compiler.py b/test/sql/test_compiler.py
index b1c807df6..8b02d12a9 100644
--- a/test/sql/test_compiler.py
+++ b/test/sql/test_compiler.py
@@ -28,6 +28,7 @@ from sqlalchemy.engine import default
 from sqlalchemy.dialects import mysql, mssql, postgresql, oracle, \
             sqlite, sybase
 from sqlalchemy.ext.compiler import compiles
+from sqlalchemy.sql import compiler
 
 table1 = table('mytable',
     column('myid', Integer),
@@ -181,6 +182,34 @@ class SelectTest(fixtures.TestBase, AssertsCompiledSQL):
                 checkparams=params
             )
 
+    def test_select_precol_compile_ordering(self):
+        s1 = select([column('x')]).select_from('a').limit(5).as_scalar()
+        s2 = select([s1]).limit(10)
+
+        class MyCompiler(compiler.SQLCompiler):
+            def get_select_precolumns(self, select):
+                result = ""
+                if select._limit:
+                    result += "FIRST %s " % self.process(literal(select._limit))
+                if select._offset:
+                    result += "SKIP %s " % self.process(literal(select._offset))
+                return result
+
+            def limit_clause(self, select):
+                return ""
+
+        dialect = default.DefaultDialect()
+        dialect.statement_compiler = MyCompiler
+        dialect.paramstyle = 'qmark'
+        dialect.positional = True
+        self.assert_compile(
+            s2,
+            "SELECT FIRST ? (SELECT FIRST ? x FROM a) AS anon_1",
+            checkpositional=(10, 5),
+            dialect=dialect
+        )
+
+
     def test_from_subquery(self):
         """tests placing select statements in the column clause of
         another select, for the