python: Rework callbacks.

Simplify how the lifetime of callback arguments is managed.

* lang/python/gpgme.i (gpgme_edit_cb_t): Check arguments.
(PyObject_p_p, void_p_p): Drop rather dangerous interface.
(pygpgme_unwrap_gpgme_ctx_t): New function.
* lang/python/helpers.c (pygpgme_clear_generic_cb): Drop dangerous
function.
(pyPassphraseCb): Assert contract.
(pygpgme_set_passphrase_cb): Use Python's calling convention so that
we can raise exceptions.  Hand in 'self', get the wrapped object, and
simply store the hook data as attribute of the wrapper object.
(pyProgressCb, pygpgme_set_progress_cb): Likewise.
(pygpgme_set_status_cb): Likewise.
(pygpgme_data_new_from_cbs): Likewise.
* lang/python/helpers.h (pygpgme_clear_generic_cb): Drop prototype.
(pygpgme_set_passphrase_cb): Update prototype.
(pygpgme_set_progress_cb): Likewise.
(pygpgme_set_status_cb): Likewise.
(pygpgme_data_new_from_cbs): Likewise.
(pygpgme_unwrap_gpgme_ctx_t): New prottotype.
* lang/python/pyme/core.py (Context, Data): Update callsites.

Signed-off-by: Justus Winter <[email protected]>

1 files changed, 19 insertions, 6 deletions

diff --git a/lang/python/gpgme.i b/lang/python/gpgme.i
index 1e4c9ff6..65cd2352 100644
--- a/lang/python/gpgme.i
+++ b/lang/python/gpgme.i
@@ -302,11 +302,14 @@
 
 // Include mapper for edit callbacks
 %typemap(in) (gpgme_edit_cb_t fnc, void *fnc_value) {
+  if (! PyTuple_Check($input))
+    return PyErr_Format(PyExc_TypeError, "edit callback must be a tuple");
+  if (PyTuple_Size($input) != 2 && PyTuple_Size($input) != 3)
+    return PyErr_Format(PyExc_TypeError,
+                        "edit callback must be a tuple of size 2 or 3");
+
   $1 = (gpgme_edit_cb_t) pyEditCb;
-  if ($input == Py_None)
-    $2 = NULL;
-  else
-    $2 = $input;
+  $2 = $input;
 }
 
 /* Include the unmodified <gpgme.h> for cc, and the cleaned-up local
@@ -355,8 +358,6 @@ struct _gpgme_sig_notation
 %pointer_functions(gpgme_error_t, gpgme_error_t_p);
 %pointer_functions(gpgme_trust_item_t, gpgme_trust_item_t_p);
 %pointer_functions(gpgme_engine_info_t, gpgme_engine_info_t_p);
-%pointer_functions(PyObject *, PyObject_p_p);
-%pointer_functions(void *, void_p_p);
 
 // Helper functions.
 
@@ -374,6 +375,18 @@ pygpgme_wrap_gpgme_data_t(gpgme_data_t data)
 {
   return SWIG_NewPointerObj(data, SWIGTYPE_p_gpgme_data, 0);
 }
+
+gpgme_ctx_t
+pygpgme_unwrap_gpgme_ctx_t(PyObject *wrapped)
+{
+  gpgme_ctx_t result;
+  if (SWIG_ConvertPtr(wrapped,
+                      (void **) &result,
+                      SWIGTYPE_p_gpgme_context,
+                      SWIG_POINTER_EXCEPTION) == -1)
+    return NULL;
+  return result;
+}
 %}
 
 %include "helpers.h"