From 646f12f6258ca512fbed2a8593854a8bcec981bf Mon Sep 17 00:00:00 2001
From: David Rose <david@ddrose.com>
Date: Thu, 16 Feb 2012 00:19:09 +0000
Subject: [PATCH] squelch backtrace on SystemExit

---
 direct/src/task/Task.py        |  3 +++
 dtool/src/pystub/pystub.cxx    |  2 ++
 panda/src/event/pythonTask.cxx | 13 +++++++++++--
 panda/src/pipeline/thread.cxx  | 30 ++++++++++++++++++------------
 4 files changed, 34 insertions(+), 14 deletions(-)

diff --git a/direct/src/task/Task.py b/direct/src/task/Task.py
index 83d9cdfbee..281c634b80 100644
--- a/direct/src/task/Task.py
+++ b/direct/src/task/Task.py
@@ -502,6 +502,9 @@ class TaskManager:
                         self.step()
                 except KeyboardInterrupt:
                     self.stop()
+                except SystemExit:
+                    self.stop()
+                    raise
                 except IOError, ioError:
                     code, message = self._unpackIOError(ioError)
                     # Since upgrading to Python 2.4.1, pausing the execution
diff --git a/dtool/src/pystub/pystub.cxx b/dtool/src/pystub/pystub.cxx
index b64a101331..7c690f79e6 100644
--- a/dtool/src/pystub/pystub.cxx
+++ b/dtool/src/pystub/pystub.cxx
@@ -147,6 +147,7 @@ extern "C" {
   EXPCL_DTOOLCONFIG extern void *PyExc_RuntimeError;
   EXPCL_DTOOLCONFIG extern void *PyExc_StandardError;
   EXPCL_DTOOLCONFIG extern void *PyExc_StopIteration;
+  EXPCL_DTOOLCONFIG extern void *PyExc_SystemExit;
   EXPCL_DTOOLCONFIG extern void *PyExc_TypeError;
   EXPCL_DTOOLCONFIG extern void *PyExc_ValueError;
   EXPCL_DTOOLCONFIG extern void *_Py_NoneStruct;
@@ -290,6 +291,7 @@ void *PyExc_IndexError = (void *)NULL;
 void *PyExc_RuntimeError = (void *)NULL;
 void *PyExc_StandardError = (void *)NULL;
 void *PyExc_StopIteration = (void *)NULL;
+void *PyExc_SystemExit = (void *)NULL;
 void *PyExc_TypeError = (void *)NULL;
 void *PyExc_ValueError = (void *)NULL;
 void *_Py_NoneStruct = (void *)NULL;
diff --git a/panda/src/event/pythonTask.cxx b/panda/src/event/pythonTask.cxx
index a8f888289f..548de2d841 100644
--- a/panda/src/event/pythonTask.cxx
+++ b/panda/src/event/pythonTask.cxx
@@ -420,8 +420,17 @@ do_python_task() {
   }
 
   if (result == (PyObject *)NULL) {
-    task_cat.error()
-      << "Exception occurred in " << *this << "\n";
+    if (PyErr_Occurred() && PyErr_ExceptionMatches(PyExc_SystemExit)) {
+      // Don't print an error message for SystemExit.  Or rather, make
+      // it a debug message.
+      if (task_cat.is_debug()) {
+        task_cat.debug()
+          << "SystemExit occurred in " << *this << "\n";
+      }
+    } else {
+      task_cat.error()
+        << "Exception occurred in " << *this << "\n";
+    }
     return DS_interrupt;
   }
 
diff --git a/panda/src/pipeline/thread.cxx b/panda/src/pipeline/thread.cxx
index a845a4f315..b33f083890 100644
--- a/panda/src/pipeline/thread.cxx
+++ b/panda/src/pipeline/thread.cxx
@@ -309,18 +309,24 @@ call_python_func(PyObject *function, PyObject *args) {
     result = PyObject_Call(function, args, NULL);
 
     if (result == (PyObject *)NULL) {
-      // Temporarily save and restore the exception state so we can print a
-      // callback on-the-spot.
-      PyObject *exc, *val, *tb;
-      PyErr_Fetch(&exc, &val, &tb);
-      
-      Py_XINCREF(exc);
-      Py_XINCREF(val);
-      Py_XINCREF(tb);
-      PyErr_Restore(exc, val, tb);
-      PyErr_Print();
-      
-      PyErr_Restore(exc, val, tb);
+      if (PyErr_Occurred() && PyErr_ExceptionMatches(PyExc_SystemExit)) {
+        // If we caught SystemExit, let it pass by without bothering
+        // to print a callback.
+
+      } else {
+        // Temporarily save and restore the exception state so we can
+        // print a callback on-the-spot.
+        PyObject *exc, *val, *tb;
+        PyErr_Fetch(&exc, &val, &tb);
+        
+        Py_XINCREF(exc);
+        Py_XINCREF(val);
+        Py_XINCREF(tb);
+        PyErr_Restore(exc, val, tb);
+        PyErr_Print();
+        
+        PyErr_Restore(exc, val, tb);
+      }
     }
 
   } else {