Patch that fixes a crash when deleting folders

[Sergio Villar Senin <svillar igalia com>]

Hi,

I'd like to commit this patch that fixes a SIGSEV in tinymail when
removing a tree of folders with messages that is just under an account
store. The problem was that the code that was notifying the removals
didn't take into account that the "self" parameter could be either an
account or a folder.

Br

Index: tny-camel-store-account.c
===================================================================
--- tny-camel-store-account.c	(revision 2716)
+++ tny-camel-store-account.c	(working copy)
@@ -86,20 +86,36 @@
 static void
 notify_folder_store_observers_about (TnyFolderStore *self, TnyFolderStoreChange *change)
 {
-	TnyCamelStoreAccountPriv *priv = TNY_CAMEL_STORE_ACCOUNT_GET_PRIVATE (self);
-	TnyCamelAccountPriv *apriv = TNY_CAMEL_ACCOUNT_GET_PRIVATE (self);
-
+	TnyCamelAccountPriv *apriv = NULL;
 	TnyIterator *iter = NULL;
-
 	TnyList *list = NULL;
 
-	g_static_rec_mutex_lock (priv->obs_lock);
-	if (!priv->sobservers) {
-		g_static_rec_mutex_unlock (priv->obs_lock);
+	GStaticRecMutex *obs_lock;
+	TnyList *sobservers;
+
+	if (TNY_IS_CAMEL_STORE_ACCOUNT (self)) {
+		TnyCamelStoreAccountPriv *priv = TNY_CAMEL_STORE_ACCOUNT_GET_PRIVATE (self);
+		apriv = TNY_CAMEL_ACCOUNT_GET_PRIVATE (self);
+
+		obs_lock = priv->obs_lock;
+		sobservers = priv->sobservers;
+	} else if (TNY_IS_CAMEL_FOLDER (self)) {
+		TnyCamelFolderPriv *priv = TNY_CAMEL_FOLDER_GET_PRIVATE (self);
+		apriv = TNY_CAMEL_ACCOUNT_GET_PRIVATE (priv->account);
+
+		obs_lock = priv->obs_lock;
+		sobservers = priv->sobservers;
+	} else {
+		g_return_if_reached ();
+	}
+
+	g_static_rec_mutex_lock (obs_lock);
+	if (!sobservers) {
+		g_static_rec_mutex_unlock (obs_lock);
 		return;
 	}
-	list = tny_list_copy (priv->sobservers);
-	g_static_rec_mutex_unlock (priv->obs_lock);
+	list = tny_list_copy (sobservers);
+	g_static_rec_mutex_unlock (obs_lock);
 
 	iter = tny_list_create_iterator (list);
 	while (!tny_iterator_is_done (iter))