correct error handling for errors other than GIT_ENOTFOUND

src/pygit2/config.c

@@ -50,18 +50,23 @@ Config_init(Config *self, PyObject *args, PyObject *kwds)
         if (!PyArg_ParseTuple(args, "s", &path)) {
             return -1;
         }
+
         err = git_config_open_ondisk(&self->config, path);
-        if (err < 0) {
+
-            Error_set_exc(PyExc_IOError);
-            return -1;
-        }
     } else {
         err = git_config_new(&self->config);
+    }
+
     if (err < 0) {
+        if (err == GIT_ENOTFOUND) {
+            Error_set_exc(PyExc_IOError);
+        } else {
             Error_set(err);
+        }
+
         return -1;
     }
-    }
+
     return 0;
 }