Also correctly initialize subsequent references to vmods.

Fixes:	878

Solved by:	tmagnien

bin/varnishd/cache_vrt_vmod.c

@@ -90,19 +90,20 @@ VRT_Vmod_Init(void **hdl, void *ptr, int len, const char *nm, const char *path)
 
 		x = dlsym(v->hdl, "Vmod_Name");
 		AN(x);
+		/* XXX: check that name is correct */
 
 		x = dlsym(v->hdl, "Vmod_Len");
 		AN(x);
 		i = x;
-		assert(len == *i);
+		v->funclen = *i;
 
 		x = dlsym(v->hdl, "Vmod_Func");
 		AN(x);
-		memcpy(ptr, x, len);
-
 		v->funcs = x;
-		v->funclen = *i;
 	}
+
+	assert(len == v->funclen);
+	memcpy(ptr, v->funcs, v->funclen);
 	v->ref++;
 
 	*hdl = v;

bin/varnishtest/tests/r00878.vtc

+#!/bin/sh
+
+test "Loading vmods in subsequent VCLs"
+
+server s1 {
+	rxreq 
+	txresp -bodylen 4
+} -start
+
+varnish v1 -vcl+backend {
+        import std from "${topbuild}/lib/libvmod_std/.libs/libvmod_std.so" ;
+	sub vcl_deliver {
+		set resp.http.who = std.author(phk);
+	}
+} -start
+
+
+client c1 {
+	txreq
+	rxresp
+} -run
+varnish v1 -vcl+backend {
+        import std from "${topbuild}/lib/libvmod_std/.libs/libvmod_std.so" ;
+	sub vcl_deliver {
+		set resp.http.who = std.author(des);
+	}
+}
+
+client c1 {
+	txreq
+	rxresp
+} -run
+
+varnish v1 -vcl+backend {
+        import std from "${topbuild}/lib/libvmod_std/.libs/libvmod_std.so" ;
+	sub vcl_deliver {
+		set resp.http.who = std.author(kristian);
+	}
+}
+
+client c1 {
+	txreq
+	rxresp
+} -run