Do not bail out of the VGZ functions if WRW fails to write, we may

still need the object.

Instead, add a WRW_error() function to query if there are WRW trouble.

Fixes	#904

bin/varnishd/cache.h

@@ -714,7 +714,6 @@ int VGZ_WrwGunzip(struct sess *, struct vgz *, void *ibuf, ssize_t ibufl,
     char *obuf, ssize_t obufl, ssize_t *obufp);
 
 /* Return values */
-#define VGZ_SOCKET	-2
 #define VGZ_ERROR	-1
 #define VGZ_OK		0
 #define VGZ_END		1
@@ -819,6 +818,7 @@ int WRK_QueueSession(struct sess *sp);
 void WRK_SumStat(struct worker *w);
 
 #define WRW_IsReleased(w)	((w)->wrw.wfd == NULL)
+int WRW_Error(const struct worker *w);
 void WRW_Chunked(struct worker *w);
 void WRW_EndChunk(struct worker *w);
 void WRW_Reserve(struct worker *w, int *fd);

bin/varnishd/cache_esi_deliver.c

@@ -327,7 +327,7 @@ ESI_Deliver(struct sess *sp)
 					i = VGZ_WrwGunzip(sp, vgz,
 						st->ptr + off, l2,
 						obuf, sizeof obuf, &obufl);
-					if (i == VGZ_SOCKET) {
+					if (WRW_Error(sp->wrk)) {
 						vca_close_session(sp,
 						    "remote closed");
 						p = e;

bin/varnishd/cache_gzip.c

@@ -379,8 +379,7 @@ VGZ_WrwGunzip(struct sess *sp, struct vgz *vg, void *ibuf, ssize_t ibufl,
 		}
 		if (obufl == *obufp || i == VGZ_STUCK) {
 			(void)WRW_Write(sp->wrk, obuf, *obufp);
-			if (WRW_Flush(sp->wrk))
-				return (VGZ_SOCKET);
+			(void)WRW_Flush(sp->wrk);
 			*obufp = 0;
 			VGZ_Obuf(vg, obuf + *obufp, obufl - *obufp);
 		}

bin/varnishd/cache_wrw.c

@@ -55,6 +55,13 @@
 /*--------------------------------------------------------------------
  */
 
+int
+WRW_Error(const struct worker *w)
+{
+
+	return (w->wrw.werr);
+}
+
 void
 WRW_Reserve(struct worker *w, int *fd)
 {