1 files changed, 20 insertions, 18 deletions

diff --git a/Modules/pyexpat.c b/Modules/pyexpat.c
index 00c96a16c7..b3259d57aa 100644
--- a/Modules/pyexpat.c
+++ b/Modules/pyexpat.c
@@ -91,7 +91,7 @@ static struct HandlerInfo handler_info[64];
  * false on an exception.
  */
 static int
-set_error_attr(PyObject *err, char *name, int value)
+set_error_attr(PyObject *err, const char *name, int value)
 {
     PyObject *v = PyLong_FromLong(value);
 
@@ -218,7 +218,7 @@ flag_error(xmlparseobject *self)
 }
 
 static PyObject*
-call_with_frame(char *funcname, int lineno, PyObject* func, PyObject* args,
+call_with_frame(const char *funcname, int lineno, PyObject* func, PyObject* args,
                 xmlparseobject *self)
 {
     PyObject *res;
@@ -747,7 +747,8 @@ pyexpat_xmlparser_Parse_impl(xmlparseobject *self, PyObject *data,
         s += MAX_CHUNK_SIZE;
         slen -= MAX_CHUNK_SIZE;
     }
-    assert(MAX_CHUNK_SIZE < INT_MAX && slen < INT_MAX);
+    Py_BUILD_ASSERT(MAX_CHUNK_SIZE <= INT_MAX);
+    assert(slen <= INT_MAX);
     rc = XML_Parse(self->itself, s, (int)slen, isfinal);
 
 done:
@@ -765,7 +766,7 @@ readinst(char *buf, int buf_size, PyObject *meth)
 {
     PyObject *str;
     Py_ssize_t len;
-    char *ptr;
+    const char *ptr;
 
     str = PyObject_CallFunction(meth, "n", buf_size);
     if (str == NULL)
@@ -1225,12 +1226,8 @@ xmlparse_dealloc(xmlparseobject *self)
     self->itself = NULL;
 
     if (self->handlers != NULL) {
-        PyObject *temp;
-        for (i = 0; handler_info[i].name != NULL; i++) {
-            temp = self->handlers[i];
-            self->handlers[i] = NULL;
-            Py_XDECREF(temp);
-        }
+        for (i = 0; handler_info[i].name != NULL; i++)
+            Py_CLEAR(self->handlers[i]);
         PyMem_Free(self->handlers);
         self->handlers = NULL;
     }
@@ -1343,7 +1340,6 @@ sethandler(xmlparseobject *self, PyObject *name, PyObject* v)
     int handlernum = handlername2int(name);
     if (handlernum >= 0) {
         xmlhandler c_handler = NULL;
-        PyObject *temp = self->handlers[handlernum];
 
         if (v == Py_None) {
             /* If this is the character data handler, and a character
@@ -1365,8 +1361,7 @@ sethandler(xmlparseobject *self, PyObject *name, PyObject* v)
             Py_INCREF(v);
             c_handler = handler_info[handlernum].handler;
         }
-        self->handlers[handlernum] = v;
-        Py_XDECREF(temp);
+        Py_XSETREF(self->handlers[handlernum], v);
         handler_info[handlernum].setter(self->itself, c_handler);
         return 1;
     }
@@ -1705,7 +1700,15 @@ MODULE_INITFUNC(void)
     PyModule_AddStringConstant(m, "native_encoding", "UTF-8");
 
     sys_modules = PySys_GetObject("modules");
+    if (sys_modules == NULL) {
+        Py_DECREF(m);
+        return NULL;
+    }
     d = PyModule_GetDict(m);
+    if (d == NULL) {
+        Py_DECREF(m);
+        return NULL;
+    }
     errors_module = PyDict_GetItem(d, errmod_name);
     if (errors_module == NULL) {
         errors_module = PyModule_New(MODULE_NAME ".errors");
@@ -1726,9 +1729,11 @@ MODULE_INITFUNC(void)
         }
     }
     Py_DECREF(modelmod_name);
-    if (errors_module == NULL || model_module == NULL)
+    if (errors_module == NULL || model_module == NULL) {
         /* Don't core dump later! */
+        Py_DECREF(m);
         return NULL;
+    }
 
 #if XML_COMBINED_VERSION > 19505
     {
@@ -1896,15 +1901,12 @@ static void
 clear_handlers(xmlparseobject *self, int initial)
 {
     int i = 0;
-    PyObject *temp;
 
     for (; handler_info[i].name != NULL; i++) {
         if (initial)
             self->handlers[i] = NULL;
         else {
-            temp = self->handlers[i];
-            self->handlers[i] = NULL;
-            Py_XDECREF(temp);
+            Py_CLEAR(self->handlers[i]);
             handler_info[i].setter(self->itself, NULL);
         }
     }