From 616f44f3c2d07af7df50ddd4e9bd391b368eafe2 Mon Sep 17 00:00:00 2001
From: Luke Lovett <luke.lovett@mongodb.com>
Date: Tue, 17 Nov 2015 11:23:56 -0800
Subject: [PATCH] PYTHON-1013 - Only reraise PyExc_Exceptions as InvalidBSON in
 get_value.

---
 bson/_cbsonmodule.c | 40 +++++++++++++++++++++-------------------
 1 file changed, 21 insertions(+), 19 deletions(-)

diff --git a/bson/_cbsonmodule.c b/bson/_cbsonmodule.c
index ada7bee0f..350c35d98 100644
--- a/bson/_cbsonmodule.c
+++ b/bson/_cbsonmodule.c
@@ -2105,27 +2105,29 @@ static PyObject* get_value(PyObject* self, const char* buffer, unsigned* positio
          * Calling _error clears the error state, so fetch it first.
          */
         PyErr_Fetch(&etype, &evalue, &etrace);
-        InvalidBSON = _error("InvalidBSON");
-        if (InvalidBSON) {
-            if (!PyErr_GivenExceptionMatches(etype, InvalidBSON)) {
-                /*
-                 * Raise InvalidBSON(str(e)).
-                 */
-                Py_DECREF(etype);
-                etype = InvalidBSON;
+        if (PyErr_GivenExceptionMatches(etype, PyExc_Exception)) {
+            InvalidBSON = _error("InvalidBSON");
+            if (InvalidBSON) {
+                if (!PyErr_GivenExceptionMatches(etype, InvalidBSON)) {
+                    /*
+                     * Raise InvalidBSON(str(e)).
+                     */
+                    Py_DECREF(etype);
+                    etype = InvalidBSON;
 
-                if (evalue) {
-                    PyObject *msg = PyObject_Str(evalue);
-                    Py_DECREF(evalue);
-                    evalue = msg;
+                    if (evalue) {
+                        PyObject *msg = PyObject_Str(evalue);
+                        Py_DECREF(evalue);
+                        evalue = msg;
+                    }
+                    PyErr_NormalizeException(&etype, &evalue, &etrace);
+                } else {
+                    /*
+                     * The current exception matches InvalidBSON, so we don't
+                     * need this reference after all.
+                     */
+                    Py_DECREF(InvalidBSON);
                 }
-                PyErr_NormalizeException(&etype, &evalue, &etrace);
-            } else {
-                /*
-                 * The current exception matches InvalidBSON, so we don't need
-                 * this reference after all.
-                 */
-                Py_DECREF(InvalidBSON);
             }
         }
         /* Steals references to args. */