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authorNeil Schemenauer <nascheme@enme.ucalgary.ca>2004-03-11 01:00:44 (GMT)
committerNeil Schemenauer <nascheme@enme.ucalgary.ca>2004-03-11 01:00:44 (GMT)
commit0eadcd9cbbc3e165f046fa01025e2a76084a8e52 (patch)
tree0ef2dd9ac88773102af7efeaa3f3452e214711ce /Objects/bufferobject.c
parent5e3a675b6d0f257a4fbd1484f0dc7cd1d20c6b22 (diff)
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Document one of the many problems with the buffer object.
Diffstat (limited to 'Objects/bufferobject.c')
-rw-r--r--Objects/bufferobject.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/Objects/bufferobject.c b/Objects/bufferobject.c
index fe2be73..561d6c1 100644
--- a/Objects/bufferobject.c
+++ b/Objects/bufferobject.c
@@ -228,10 +228,17 @@ buffer_hash(PyBufferObject *self)
if ( self->b_hash != -1 )
return self->b_hash;
+ /* XXX potential bugs here, a readonly buffer does not imply that the
+ * underlying memory is immutable. b_readonly is a necessary but not
+ * sufficient condition for a buffer to be hashable. Perhaps it would
+ * be better to only allow hashing if the underlying object is known to
+ * be immutable (e.g. PyString_Check() is true). Another idea would
+ * be to call tp_hash on the underlying object and see if it raises
+ * an error. */
if ( !self->b_readonly )
{
- /* ### use different wording, since this is conditional? */
- PyErr_SetString(PyExc_TypeError, "unhashable type");
+ PyErr_SetString(PyExc_TypeError,
+ "writable buffers are not hashable");
return -1;
}