[Libguestfs] [PATCH] python: Call PyErr_Clear() on non-error paths out of the Python bindings.
We also need to be more careful about PyString_FromString and similar
functions returning NULL on failure. Currently we don't check this
every time. This commit adds more checks, but is still not complete.
---
TODO | 6 ------
generator/python.ml | 19 +++++++++++++++----
2 files changed, 15 insertions(+), 10 deletions(-)
diff --git a/TODO b/TODO
index 075bdc6..666400e 100644
--- a/TODO
+++ b/TODO
@@ -563,12 +563,6 @@ Write an extension for mc that would let people browse into
filesystems. See
http://repo.or.cz/w/midnight-commander.git/tree/HEAD:/misc/ext.d
-Python
-------
-
-It seems as if we should call PyErr_Clear() somewhere in every
-Python binding.
-
Improvements in virt-log
------------------------
diff --git a/generator/python.ml b/generator/python.ml
index 4b823e6..637f22d 100644
--- a/generator/python.ml
+++ b/generator/python.ml
@@ -455,7 +455,8 @@ put_table (char * const * const argv)
pr " py_r = PyString_FromString (r);\n";
pr "#else\n";
pr " py_r = PyUnicode_FromString (r);\n";
- pr "#endif\n"
+ pr "#endif\n";
+ pr " if (py_r == NULL) goto out;\n";
| RConstOptString _ ->
pr " if (r) {\n";
pr "#ifdef HAVE_PYSTRING_ASSTRING\n";
@@ -466,14 +467,16 @@ put_table (char * const * const argv)
pr " } else {\n";
pr " Py_INCREF (Py_None);\n";
pr " py_r = Py_None;\n";
- pr " }\n"
+ pr " }\n";
+ pr " if (py_r == NULL) goto out;\n";
| RString _ ->
pr "#ifdef HAVE_PYSTRING_ASSTRING\n";
pr " py_r = PyString_FromString (r);\n";
pr "#else\n";
pr " py_r = PyUnicode_FromString (r);\n";
pr "#endif\n";
- pr " free (r);\n"
+ pr " free (r);\n";
+ pr " if (py_r == NULL) goto out;\n";
| RStringList _ ->
pr " py_r = put_string_list (r);\n";
pr " guestfs_int_free_string_list (r);\n"
@@ -492,10 +495,18 @@ put_table (char * const * const argv)
pr "#else\n";
pr " py_r = PyBytes_FromStringAndSize (r, size);\n";
pr "#endif\n";
- pr " free (r);\n"
+ pr " free (r);\n";
+ pr " if (py_r == NULL) goto out;\n";
);
+ (* As this is the non-error path, clear the Python error
+ * indicator flag in case it was set accidentally somewhere in
+ * the function. Since we are not returning an error indication
+ * to the caller, having it set would risk the error popping up
+ * at random later in the interpreter.
+ *)
pr "\n";
+ pr " PyErr_Clear ();\n";
pr " out:\n";
List.iter (
--
2.1.0