fix for empty filters in inline streams

3 files changed, 12 insertions, 4 deletions

diff --git a/mupdf/pdf_image.c b/mupdf/pdf_image.c
index c081d4f3..1d510ab9 100644
--- a/mupdf/pdf_image.c
+++ b/mupdf/pdf_image.c
@@ -131,6 +131,9 @@ pdf_loadinlineimage(pdf_image **imgp, pdf_xref *xref,
 		if (error)
 			return error;
 
+		if (filter == nil)
+		    goto thereisnofilter;
+
 		error = fz_openrfilter(&tempfile, filter, file);
 		if (error)
 			return error;
@@ -144,6 +147,7 @@ pdf_loadinlineimage(pdf_image **imgp, pdf_xref *xref,
 	}
 	else
 	{
+thereisnofilter:
 		error = fz_newbuffer(&img->samples, img->super.h * img->stride);
 		if (error)
 			return error;
diff --git a/mupdf/pdf_stream.c b/mupdf/pdf_stream.c
index f7a18970..8717ed26 100644
--- a/mupdf/pdf_stream.c
+++ b/mupdf/pdf_stream.c
@@ -232,15 +232,17 @@ pdf_buildinlinefilter(fz_filter **filterp, fz_obj *stmobj)
 	filters = fz_dictgetsa(stmobj, "Filter", "F");
 	params = fz_dictgetsa(stmobj, "DecodeParms", "DP");
 
+	*filterp = nil;
+
 	if (filters)
 	{
 		if (fz_isname(filters))
 			return buildonefilter(filterp, filters, params);
-		else
+		else if (fz_arraylen(filters) > 0)
 			return buildfilterchain(filterp, nil, filters, params);
 	}
-	else
-		return fz_newnullfilter(filterp, -1);
+
+	/* uh oh, no filter */
 
 	return nil;
 }
diff --git a/stream/filt_null.c b/stream/filt_null.c
index d2c068e9..f51039b4 100644
--- a/stream/filt_null.c
+++ b/stream/filt_null.c
@@ -30,7 +30,9 @@ fz_processnullfilter(fz_filter *filter, fz_buffer *in, fz_buffer *out)
 	fz_nullfilter *f = (fz_nullfilter*)filter;
 	int n;
 
-	n = MIN(MIN(in->wp - in->rp, out->ep - out->wp), f->len - f->cur);
+	n = MIN(in->wp - in->rp, out->ep - out->wp);
+	if (f->len >= 0)
+	    n = MIN(n, f->len - f->cur);
 
 	if (n) {
 		memcpy(out->wp, in->rp, n);