Set the default lgwin value in the encoder constructor.

README.rst

@@ -78,7 +78,7 @@ new xencoder = brotli.encoder(STRING name, BYTES bufffer, INT quality, BOOL larg
       BYTES bufffer=32768,
       INT quality=11,
       BOOL large_win=0,
-      INT lgwin=0
+      INT lgwin=22
    )
 
 XXX ...

src/vfp_brotli.c

@@ -772,8 +772,7 @@ vmod_encoder__init(VRT_CTX, struct vmod_brotli_encoder **encp,
 		return;
 	}
 
-	if (lgwin != 0 &&
-	    (lgwin < BROTLI_MIN_WINDOW_BITS || lgwin > BROTLI_MAX_WINDOW_BITS)) {
+	if (lgwin < BROTLI_MIN_WINDOW_BITS || lgwin > BROTLI_MAX_WINDOW_BITS) {
 		VFAIL(ctx, "new %s: lgwin %ld out of range (%d to %d)",
 		      vcl_name, lgwin, BROTLI_MIN_WINDOW_BITS,
 		      BROTLI_MAX_WINDOW_BITS);

src/vfp_brotli.vcc

@@ -63,7 +63,7 @@ algorithm for responses fetched from backends.
 XXX ...
 
 $Object encoder(PRIV_VCL, STRING name, BYTES bufffer=32768, INT quality=11,
-                BOOL large_win=0, INT lgwin=0)
+                BOOL large_win=0, INT lgwin=22)
 
 XXX ...