1 files changed, 45 insertions, 11 deletions

diff --git a/stream/filt_flate.c b/stream/filt_flate.c
index c34a49b7..777d6d56 100644
--- a/stream/filt_flate.c
+++ b/stream/filt_flate.c
@@ -21,6 +21,8 @@ fz_error *
 fz_newflated(fz_filter **fp, fz_obj *params)
 {
 	fz_error *eo;
+	fz_obj *obj;
+	int zipfmt;
 	int ei;
 
 	FZ_NEWFILTER(fz_flate, f, flated);
@@ -31,8 +33,24 @@ fz_newflated(fz_filter **fp, fz_obj *params)
 	f->z.next_in = nil;
 	f->z.avail_in = 0;
 
-	ei = inflateInit(&f->z);
-	if (ei != Z_OK) {
+	zipfmt = 0;
+
+	if (params)
+	{
+		obj = fz_dictgets(params, "ZIP");
+		if (obj) zipfmt = fz_tobool(obj);
+	}
+
+	if (zipfmt)
+	{
+		/* if windowbits is negative the zlib header is skipped */
+		ei = inflateInit2(&f->z, -15);
+	}
+	else
+		ei = inflateInit(&f->z);
+
+	if (ei != Z_OK)
+	{
 		eo = fz_throw("ioerror: inflateInit: %s", f->z.msg);
 		fz_free(f);
 		return eo;
@@ -74,18 +92,21 @@ fz_processflated(fz_filter *f, fz_buffer *in, fz_buffer *out)
 	in->rp = in->wp - zp->avail_in;
 	out->wp = out->ep - zp->avail_out;
 
-	if (err == Z_STREAM_END) {
+	if (err == Z_STREAM_END)
+	{
 		out->eof = 1;
 		return fz_iodone;
 	}
-	else if (err == Z_OK) {
+	else if (err == Z_OK)
+	{
 		if (in->rp == in->wp && !in->eof)
 			return fz_ioneedin;
 		if (out->wp == out->ep)
 			return fz_ioneedout;
 		return fz_ioneedin; /* hmm, what's going on here? */
 	}
-	else {
+	else
+	{
 		return fz_throw("ioerror: inflate: %s", zp->msg);
 	}
 }
@@ -96,15 +117,20 @@ fz_newflatee(fz_filter **fp, fz_obj *params)
 	fz_obj *obj;
 	fz_error *eo;
 	int effort;
+	int zipfmt;
 	int ei;
 
 	FZ_NEWFILTER(fz_flate, f, flatee);
 
 	effort = -1;
+	zipfmt = 0;
 
-	if (params) {
+	if (params)
+	{
 		obj = fz_dictgets(params, "Effort");
 		if (obj) effort = fz_toint(obj);
+		obj = fz_dictgets(params, "ZIP");
+		if (obj) effort = fz_tobool(obj);
 	}
 
 	f->z.zalloc = zmalloc;
@@ -113,8 +139,13 @@ fz_newflatee(fz_filter **fp, fz_obj *params)
 	f->z.next_in = nil;
 	f->z.avail_in = 0;
 
-	ei = deflateInit(&f->z, effort);
-	if (ei != Z_OK) {
+	if (zipfmt)
+		ei = deflateInit2(&f->z, effort, Z_DEFLATED, -15, 8, Z_DEFAULT_STRATEGY);
+	else
+		ei = deflateInit(&f->z, effort);
+
+	if (ei != Z_OK)
+	{
 		eo = fz_throw("ioerror: deflateInit: %s", f->z.msg);
 		fz_free(f);
 		return eo;
@@ -158,18 +189,21 @@ fz_processflatee(fz_filter *f, fz_buffer *in, fz_buffer *out)
 	in->rp = in->wp - zp->avail_in;
 	out->wp = out->ep - zp->avail_out;
 
-	if (err == Z_STREAM_END) {
+	if (err == Z_STREAM_END)
+	{
 		out->eof = 1;
 		return fz_iodone;
 	}
-	else if (err == Z_OK) {
+	else if (err == Z_OK)
+	{
 		if (in->rp == in->wp && !in->eof)
 			return fz_ioneedin;
 		if (out->wp == out->ep)
 			return fz_ioneedout;
 		return fz_ioneedin; /* hmm? */
 	}
-	else {
+	else
+	{
 		return fz_throw("ioerror: deflate: %s", zp->msg);
 	}
 }