[libpeas] Do not reveal Python loader internals in tracebacks

[Garrett Regier <gregier src gnome org>]

commit fc3d26ff0f12c16941e5ff0501b01316d8df8deb
Author: Garrett Regier <garrettregier gmail com>
Date:   Tue Jan 20 01:13:45 2015 -0800

    Do not reveal Python loader internals in tracebacks
    
    This adds format_plugin_exception() which
    removes all internal Python frames from the traceback.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=742349

 loaders/python/peas-python-internal.c  |    2 ++
 loaders/python/peas-python-internal.py |   15 ++++++++++++++-
 2 files changed, 16 insertions(+), 1 deletions(-)
---
diff --git a/loaders/python/peas-python-internal.c b/loaders/python/peas-python-internal.c
index 227c1b5..dca8e61 100644
--- a/loaders/python/peas-python-internal.c
+++ b/loaders/python/peas-python-internal.c
@@ -116,6 +116,8 @@ peas_python_internal_new (gboolean already_initialized)
   module = PyModule_New ("libpeas-internal");
   goto_error_if_failed (module != NULL);
 
+  goto_error_if_failed (PyModule_AddStringConstant (module, "__file__",
+                                                    "peas-python-internal.py") == 0);
   goto_error_if_failed (PyModule_AddObject (module, "__builtins__",
                                             builtins_module) == 0);
   goto_error_if_failed (PyModule_AddObject (module, "ALREADY_INITIALIZED",
diff --git a/loaders/python/peas-python-internal.py b/loaders/python/peas-python-internal.py
index dcffaeb..d14b4d8 100644
--- a/loaders/python/peas-python-internal.py
+++ b/loaders/python/peas-python-internal.py
@@ -58,6 +58,19 @@ class Hooks(object):
         # This is implemented by the plugin loader
         raise NotImplementedError('Hooks.failed()')
 
+    @staticmethod
+    def format_plugin_exception():
+        formatted = traceback.format_exception(*sys.exc_info())
+
+        # Remove all mentions of this file
+        for i in range(len(formatted)):
+            if __file__ in formatted[i]:
+                while not formatted[i].startswith('Traceback'):
+                    formatted[i] = ''
+                    i -= 1
+
+        return ''.join(formatted)
+
     def call(self, name, args, return_type):
         try:
             result = getattr(self, name)(*args)
@@ -99,7 +112,7 @@ class Hooks(object):
         except:
             module = None
             self.failed("Error importing plugin '%s':\n%s" %
-                        (module_name, traceback.format_exc()))
+                        (module_name, self.format_plugin_exception()))
 
         else:
             self.__extension_cache[module] = {}