[gtksourceview] Protect functions against being called when highlighting is disabled

[Jesse van den Kieboom <jessevdk src gnome org>]

commit 9b681ac75bcfbf90adbbdb46e825d9d0db9dbbb7
Author: Jesse van den Kieboom <jessevdk gnome org>
Date:   Sun Feb 28 23:31:24 2010 +0100

    Protect functions against being called when highlighting is disabled

 gtksourceview/gtksourcecontextengine.c |   16 +++++++++++++++-
 1 files changed, 15 insertions(+), 1 deletions(-)
---
diff --git a/gtksourceview/gtksourcecontextengine.c b/gtksourceview/gtksourcecontextengine.c
index 29a0be0..aed4d2a 100644
--- a/gtksourceview/gtksourcecontextengine.c
+++ b/gtksourceview/gtksourcecontextengine.c
@@ -2001,6 +2001,12 @@ gtk_source_context_engine_text_inserted (GtkSourceEngine *engine,
 	GtkTextIter iter;
 	GtkSourceContextEngine *ce = GTK_SOURCE_CONTEXT_ENGINE (engine);
 
+	/* Happens when highlighting is disabled */
+	if (ce->priv->buffer == NULL)
+	{
+		return;
+	}
+
 	g_return_if_fail (start_offset < end_offset);
 
 	invalidate_region (ce, start_offset, end_offset - start_offset);
@@ -2766,7 +2772,15 @@ static GtkTextTag *
 gtk_source_context_engine_get_context_class_tag (GtkSourceEngine *engine,
 						 const gchar     *context_class)
 {
-	return g_hash_table_lookup (GTK_SOURCE_CONTEXT_ENGINE (engine)->priv->context_classes,
+	GHashTable *hash_table = GTK_SOURCE_CONTEXT_ENGINE (engine)->priv->context_classes;
+
+	if (hash_table == NULL)
+	{
+		/* This happens when highlighting is disabled */
+		return NULL;
+	}
+
+	return g_hash_table_lookup (hash_table,
 				    context_class);
 }