mail-autofilter.c: Add argument guards in public functions.

This is related to bug #650587, but is not a proper fix.  The proper fix
is in the next couple commits about EMailReader action groups.

This commit just trades a crash for a runtime warning, but can be
backported to the stable branch, whereas the changes required for the
proper fix are too extensive to backport.

1 files changed, 13 insertions, 1 deletions

diff --git a/mail/mail-autofilter.c b/mail/mail-autofilter.c
index f56135bf60..56cc5e9813 100644
--- a/mail/mail-autofilter.c
+++ b/mail/mail-autofilter.c
@@ -319,6 +319,10 @@ em_vfolder_rule_from_message (EMVFolderContext *context,
 	EMailSession *session;
 	gchar *uri;
 
+	g_return_val_if_fail (EM_IS_VFOLDER_CONTEXT (context), NULL);
+	g_return_val_if_fail (CAMEL_IS_MIME_MESSAGE (msg), NULL);
+	g_return_val_if_fail (CAMEL_IS_FOLDER (folder), NULL);
+
 	uri = e_mail_folder_uri_from_folder (folder);
 
 	session = em_vfolder_context_get_session (context);
@@ -342,6 +346,10 @@ em_vfolder_rule_from_address (EMVFolderContext *context,
 	EMailSession *session;
 	gchar *uri;
 
+	g_return_val_if_fail (EM_IS_VFOLDER_CONTEXT (context), NULL);
+	g_return_val_if_fail (CAMEL_IS_INTERNET_ADDRESS (addr), NULL);
+	g_return_val_if_fail (CAMEL_IS_FOLDER (folder), NULL);
+
 	uri = e_mail_folder_uri_from_folder (folder);
 
 	session = em_vfolder_context_get_session (context);
@@ -363,6 +371,9 @@ filter_rule_from_message (EMFilterContext *context,
 	EFilterRule *rule;
 	EFilterPart *part;
 
+	g_return_val_if_fail (EM_IS_FILTER_CONTEXT (context), NULL);
+	g_return_val_if_fail (CAMEL_IS_MIME_MESSAGE (msg), NULL);
+
 	rule = em_filter_rule_new ();
 	rule_from_message (rule, E_RULE_CONTEXT (context), msg, flags);
 
@@ -385,7 +396,8 @@ filter_gui_add_from_message (EMailSession *session,
 	gchar *user, *system;
 	EFilterRule *rule;
 
-	g_return_if_fail (msg != NULL);
+	g_return_if_fail (E_IS_MAIL_SESSION (session));
+	g_return_if_fail (CAMEL_IS_MIME_MESSAGE (msg));
 
 	fc = em_filter_context_new (session);
 	config_dir = mail_session_get_config_dir ();