Issue 13296: Fix IDLE to clear compile __future__ flags on shell restart.
(Patch by Roger Serwy)
diff --git a/Lib/idlelib/PyShell.py b/Lib/idlelib/PyShell.py
index 9dd43cf..ce83f19 100644
--- a/Lib/idlelib/PyShell.py
+++ b/Lib/idlelib/PyShell.py
@@ -344,6 +344,7 @@
         self.restarting = False
         self.subprocess_arglist = None
         self.port = PORT
+        self.original_compiler_flags = self.compile.compiler.flags
 
     rpcclt = None
     rpcpid = None
@@ -459,6 +460,7 @@
             gui = RemoteDebugger.restart_subprocess_debugger(self.rpcclt)
             # reload remote debugger breakpoints for all PyShellEditWindows
             debug.load_breakpoints()
+        self.compile.compiler.flags = self.original_compiler_flags
         self.restarting = False
         return self.rpcclt