Nul terminate lacbytequeue

1 files changed, 34 insertions, 11 deletions

diff --git a/src/lacbytequeue.c b/src/lacbytequeue.c
index 6761430..e2cb53a 100644
--- a/src/lacbytequeue.c
+++ b/src/lacbytequeue.c
@@ -9,15 +9,21 @@ struct LacByteQueue
     guint8 *	end;
 };
 
-LacByteQueue *
-lac_byte_queue_new (void)
+static void
+initialize (LacByteQueue *queue)
 {
-    LacByteQueue *queue = g_new0 (LacByteQueue, 1);
-    
     queue->segment_size = 0;
     queue->segment = NULL;
     queue->start = NULL;
     queue->end = NULL;
+}
+
+LacByteQueue *
+lac_byte_queue_new (void)
+{
+    LacByteQueue *queue = g_new0 (LacByteQueue, 1);
+
+    initialize (queue);
     
     return queue;
 }
@@ -62,7 +68,7 @@ const guint8 *
 lac_byte_queue_get_data (LacByteQueue *queue,
 			 gsize        *n_bytes)
 {
-    guint8 *result;
+    const guint8 *result;
     
     if (n_bytes)
 	*n_bytes = queue->end - queue->start;
@@ -71,6 +77,11 @@ lac_byte_queue_get_data (LacByteQueue *queue,
     
     queue->start = queue->segment;
     queue->end = queue->segment;
+
+    if (!result)
+	result = (guint8 *)"";   /* the result of this function is guaranteed
+				  * to be NULL terminated
+				  */
     
     return result;
 }
@@ -101,13 +112,20 @@ power_of_two_bigger_than (gsize n)
 }
 
 static void
+null_terminate (LacByteQueue *queue)
+{
+    if (queue->end)
+	*(queue->end) = '\0';
+}
+
+static void
 ensure_room (LacByteQueue *queue,
 	     gsize      extra)
 {
     gsize old_data_size = queue->end - queue->start;
     gsize new_data_size = old_data_size + extra;
     
-    if (queue->end + new_data_size > queue->segment + queue->segment_size)
+    if (queue->end + new_data_size + 1 > queue->segment + queue->segment_size)
     {
 	gsize new_segment_size = power_of_two_bigger_than (2 * new_data_size);
 	
@@ -121,6 +139,8 @@ ensure_room (LacByteQueue *queue,
 	
 	queue->start = queue->segment;
 	queue->end = queue->start + old_data_size;
+
+	null_terminate (queue);
     }
 }
 
@@ -156,6 +176,8 @@ lac_byte_queue_alloc_tail (LacByteQueue *queue,
     ensure_room (queue, size);
     
     queue->end += size;
+
+    null_terminate (queue);
     
     return queue->end - size;
 }
@@ -168,6 +190,8 @@ lac_byte_queue_delete_tail (LacByteQueue *queue,
 	queue->end = queue->start;
     else
 	queue->end -= size;
+
+    null_terminate (queue);
 }
 
 void
@@ -186,6 +210,8 @@ lac_byte_queue_append (LacByteQueue    *queue,
 	
 	memcpy (tail, bytes, n_bytes);
     }
+
+    null_terminate (queue);
 }
 
 /* Transfer data from @src to @dest, if possible without copying.
@@ -204,11 +230,8 @@ lac_byte_queue_steal_data (LacByteQueue    *dest,
 	dest->segment = src->segment;
 	dest->start = src->start;
 	dest->end = src->end;
-	
-	src->segment_size = 0;
-	src->segment = NULL;
-	src->start = NULL;
-	src->end = NULL;
+
+	initialize (src);
     }
     else
     {