- Threadlocal engine methods rollback(), commit(),

prepare() won't raise if no transaction is in progress;
this was a regression introduced in 0.6.  [ticket:1998]

CHANGES

@@ -77,6 +77,10 @@ CHANGES
     "collections.Sequence" registration for RowProxy.
     [ticket:1871]
 
+  - Threadlocal engine methods rollback(), commit(),
+    prepare() won't raise if no transaction is in progress;
+    this was a regression introduced in 0.6.  [ticket:1998]
+    
 - postgresql
   - Single element tuple expressions inside an IN clause
     parenthesize correctly, also from [ticket:1984]

lib/sqlalchemy/engine/threadlocal.py

@@ -77,16 +77,22 @@ class TLEngine(base.Engine):
         self._connections.trans.append(self.contextual_connect().begin())
         
     def prepare(self):
+        if not self._connections.trans:
+            return
         self._connections.trans[-1].prepare()
         
     def commit(self):
+        if not self._connections.trans:
+            return
         trans = self._connections.trans.pop(-1)
         trans.commit()
         
     def rollback(self):
+        if not self._connections.trans:
+            return
         trans = self._connections.trans.pop(-1)
         trans.rollback()
-    
+        
     def dispose(self):
         self._connections = util.threading.local()
         super(TLEngine, self).dispose()

test/engine/test_transaction.py

@@ -541,7 +541,19 @@ class TLTransactionTest(TestBase):
         # ensure tests start with engine closed
 
         tlengine.close()
+    
+    def test_rollback_no_trans(self):
+        # shouldn't fail
+        tlengine.rollback()
 
+    def test_commit_no_trans(self):
+        # shouldn't fail
+        tlengine.commit()
+
+    def test_prepare_no_trans(self):
+        # shouldn't fail
+        tlengine.prepare()
+        
     def test_connection_close(self):
         """test that when connections are closed for real, transactions
         are rolled back and disposed."""