commit 15a40394b0c21829ba9afbb739b2038b8211dabe
author Guido van Rossum <guido@python.org> Wed Sep 03 00:09:26 1997 +0000
committer Guido van Rossum <guido@python.org> Wed Sep 03 00:09:26 1997 +0000
tree 007e934a360eeac8e87c76c0327d960db81c5fb4
parent 2d30840b92d19f2229da75f47a5c7e8cbd254981

Fix the bug Jeremy was experiencing: both the close() and the
dealloc() functions contained code to free/DECREF the buffer
(there were differences between I and O objects but the logic bug was
the same).  Fixed this be setting the buffer pointer to NULL and
testing for that.  (This also makes it safe to call close() more than
once.)

XXX Worry: what if you try to read() or write() once the thing is
closed?

Modules/cStringIO.c

diff --git a/Modules/cStringIO.c b/Modules/cStringIO.c
index 09b4051..b08c899 100644
--- a/Modules/cStringIO.c
+++ b/Modules/cStringIO.c
@@ -314,7 +314,9 @@
 
 static PyObject *
 O_close(Oobject *self, PyObject *args) {
-  free(self->buf);
+  if (self->buf != NULL)
+    free(self->buf);
+  self->buf = NULL;
 
   self->pos = self->string_size = self->buf_size = 0;
   self->closed = 1;
@@ -392,7 +394,8 @@
 
 static void
 O_dealloc(Oobject *self) {
-  free(self->buf);
+  if (self->buf != NULL)
+    free(self->buf);
   PyMem_DEL(self);
 }
 
@@ -475,7 +478,8 @@
 
 static PyObject *
 I_close(Iobject *self, PyObject *args) {
-  Py_DECREF(self->pbuf);
+  Py_XDECREF(self->pbuf);
+  self->pbuf = NULL;
 
   self->pos = self->string_size = 0;
   self->closed = 1;
@@ -499,7 +503,7 @@
 
 static void
 I_dealloc(Iobject *self) {
-  Py_DECREF(self->pbuf);
+  Py_XDECREF(self->pbuf);
   PyMem_DEL(self);
 }
 
@@ -627,6 +631,17 @@
 /******************************************************************************
 
   $Log$
+  Revision 2.7  1997/09/03 00:09:26  guido
+  Fix the bug Jeremy was experiencing: both the close() and the
+  dealloc() functions contained code to free/DECREF the buffer
+  (there were differences between I and O objects but the logic bug was
+  the same).  Fixed this be setting the buffer pointer to NULL and
+  testing for that.  (This also makes it safe to call close() more than
+  once.)
+
+  XXX Worry: what if you try to read() or write() once the thing is
+  closed?
+
   Revision 2.6  1997/08/13 03:14:41  guido
   cPickle release 0.3 from Jim Fulton