Issue #4509: bugs in bytearray with exports (buffer protocol)

1 files changed, 31 insertions, 11 deletions

diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c
index 99bb0f2..d75eb53 100644
--- a/Objects/bytearrayobject.c
+++ b/Objects/bytearrayobject.c
@@ -154,6 +154,17 @@ _getbuffer(PyObject *obj, Py_buffer *view)
     return view->len;
 }
 
+static int
+_canresize(PyByteArrayObject *self)
+{
+    if (self->ob_exports > 0) {
+        PyErr_SetString(PyExc_BufferError,
+                "Existing exports of data: object cannot be re-sized");
+        return 0;
+    }
+    return 1;
+}
+
 /* Direct API functions */
 
 PyObject *
@@ -229,6 +240,13 @@ PyByteArray_Resize(PyObject *self, Py_ssize_t size)
     assert(PyByteArray_Check(self));
     assert(size >= 0);
 
+    if (size == Py_SIZE(self)) {
+        return 0;
+    }
+    if (!_canresize((PyByteArrayObject *)self)) {
+        return -1;
+    }
+
     if (size < alloc / 2) {
         /* Major downsize; resize down to exact size */
         alloc = size + 1;
@@ -248,16 +266,6 @@ PyByteArray_Resize(PyObject *self, Py_ssize_t size)
         alloc = size + 1;
     }
 
-    if (((PyByteArrayObject *)self)->ob_exports > 0) {
-            /*
-            fprintf(stderr, "%d: %s", ((PyByteArrayObject *)self)->ob_exports,
-                    ((PyByteArrayObject *)self)->ob_bytes);
-            */
-            PyErr_SetString(PyExc_BufferError,
-                    "Existing exports of data: object cannot be re-sized");
-            return -1;
-    }
-
     sval = PyMem_Realloc(((PyByteArrayObject *)self)->ob_bytes, alloc);
     if (sval == NULL) {
         PyErr_NoMemory();
@@ -522,6 +530,10 @@ bytes_setslice(PyByteArrayObject *self, Py_ssize_t lo, Py_ssize_t hi,
 
     if (avail != needed) {
         if (avail > needed) {
+            if (!_canresize(self)) {
+                res = -1;
+                goto finish;
+            }
             /*
               0   lo               hi               old_size
               |   |<----avail----->|<-----tomove------>|
@@ -654,6 +666,8 @@ bytes_ass_subscript(PyByteArrayObject *self, PyObject *index, PyObject *values)
         stop = start;
     if (step == 1) {
         if (slicelen != needed) {
+            if (!_canresize(self))
+                return -1;
             if (slicelen > needed) {
                 /*
                   0   start           stop              old_size
@@ -689,6 +703,8 @@ bytes_ass_subscript(PyByteArrayObject *self, PyObject *index, PyObject *values)
             /* Delete slice */
             Py_ssize_t cur, i;
 
+            if (!_canresize(self))
+                return -1;
             if (step < 0) {
                 stop = start + 1;
                 start = stop + step * (slicelen - 1) - 1;
@@ -1473,7 +1489,7 @@ bytes_translate(PyByteArrayObject *self, PyObject *args)
         }
         goto done;
     }
-
+    
     for (i = 0; i < 256; i++)
         trans_table[i] = Py_CHARMASK(table[i]);
 
@@ -2730,6 +2746,8 @@ bytes_pop(PyByteArrayObject *self, PyObject *args)
         PyErr_SetString(PyExc_IndexError, "pop index out of range");
         return NULL;
     }
+    if (!_canresize(self))
+        return NULL;
 
     value = self->ob_bytes[where];
     memmove(self->ob_bytes + where, self->ob_bytes + where + 1, n - where);
@@ -2760,6 +2778,8 @@ bytes_remove(PyByteArrayObject *self, PyObject *arg)
         PyErr_SetString(PyExc_ValueError, "value not found in bytes");
         return NULL;
     }
+    if (!_canresize(self))
+        return NULL;
 
     memmove(self->ob_bytes + where, self->ob_bytes + where + 1, n - where);
     if (PyByteArray_Resize((PyObject *)self, n - 1) < 0)