diff -up ghostscript-8.71/jbig2dec/jbig2_image.c.jbig2-image-refcount ghostscript-8.71/jbig2dec/jbig2_image.c

--- ghostscript-8.71/jbig2dec/jbig2_image.c.jbig2-image-refcount	2010-08-05 14:55:56.417043303 +0100

+++ ghostscript-8.71/jbig2dec/jbig2_image.c	2010-08-05 14:56:46.796169065 +0100

@@ -60,15 +60,18 @@ Jbig2Image* jbig2_image_new(Jbig2Ctx *ct

 /* clone an image pointer by bumping its reference count */

 Jbig2Image* jbig2_image_clone(Jbig2Ctx *ctx, Jbig2Image *image)

 {

-	image->refcount++;

+	if (image)

+		image->refcount++;

 	return image;

 }

 /* release an image pointer, freeing it it appropriate */

 void jbig2_image_release(Jbig2Ctx *ctx, Jbig2Image *image)

 {

-	image->refcount--;

-	if (!image->refcount) jbig2_image_free(ctx, image);

+	if (image) {

+		image->refcount--;

+		if (!image->refcount) jbig2_image_free(ctx, image);

+	}

 }

 /* free a Jbig2Image structure and its associated memory */