1 files changed, 26 insertions, 1 deletions

diff --git a/filter/buffer.c b/filter/buffer.c
index 7b728b9b..25e30a55 100644
--- a/filter/buffer.c
+++ b/filter/buffer.c
@@ -8,6 +8,7 @@ fz_newbuffer(fz_buffer **bp, int size)
 	b = *bp = fz_malloc(sizeof(fz_buffer));
 	if (!b) return fz_outofmem;
 
+	b->ownsdata = 1;
 	b->bp = fz_malloc(size);
 	if (!b->bp) { fz_free(b); return fz_outofmem; }
 
@@ -19,10 +20,31 @@ fz_newbuffer(fz_buffer **bp, int size)
 	return nil;
 }
 
+fz_error *
+fz_newbufferwithdata(fz_buffer **bp, unsigned char *data, int size)
+{
+	fz_buffer *b;
+
+	b = *bp = fz_malloc(sizeof(fz_buffer));
+	if (!b) return fz_outofmem;
+
+	b->ownsdata = 0;
+	b->bp = data;
+
+	b->rp = b->bp;
+	b->wp = b->bp;
+	b->ep = b->bp + size;
+	b->eof = 0;
+
+	return nil;
+}
+
+
 void
 fz_freebuffer(fz_buffer *buf)
 {
-	fz_free(buf->bp);
+	if (buf->ownsdata)
+		fz_free(buf->bp);
 	fz_free(buf);
 }
 
@@ -35,6 +57,8 @@ fz_growbuffer(fz_buffer *buf)
 	int wp = buf->wp - buf->bp;
 	int ep = buf->ep - buf->bp;
 
+	assert(buf->ownsdata);
+
 	newbp = fz_realloc(buf->bp, ep * 2);
 	if (!newbp) return fz_outofmem;
 
@@ -49,6 +73,7 @@ fz_growbuffer(fz_buffer *buf)
 fz_error *
 fz_rewindbuffer(fz_buffer *buf)
 {
+	assert(buf->ownsdata);
 	memmove(buf->bp, buf->rp, buf->wp - buf->rp);
 	buf->wp = buf->bp + (buf->wp - buf->rp);
 	buf->rp = buf->bp;