[6.0] bbe46aa94 Add test case for large req body buffer use

[Dridi Boukelmoune]

commit bbe46aa94bc0b6485ca5c4bef43a7690a98459af
Author: Martin Blix Grydeland <martin at varnish-software.com>
Date:   Tue Jun 22 11:49:46 2021 +0200

    Add test case for large req body buffer use

diff --git a/bin/varnishtest/tests/t02018.vtc b/bin/varnishtest/tests/t02018.vtc
new file mode 100644
index 000000000..b6ff9eec8
--- /dev/null
+++ b/bin/varnishtest/tests/t02018.vtc
@@ -0,0 +1,36 @@
+varnishtest "H/2 stream multiple buffer exhaustion"
+
+server s1 {
+	rxreq
+	txresp
+} -start
+
+varnish v1 -vcl+backend {
+} -start
+
+varnish v1 -cliok "param.set feature +http2"
+varnish v1 -cliok "param.reset h2_initial_window_size"
+varnish v1 -cliok "param.reset h2_rx_window_low_water"
+
+client c1 {
+	stream 1 {
+		txreq -req GET -url /1 -hdr "content-length" "131072" -nostrend
+		txdata -datalen 16384 -nostrend
+		rxwinup
+		txdata -datalen 16384 -nostrend
+		rxwinup
+		txdata -datalen 16384 -nostrend
+		rxwinup
+		txdata -datalen 16384 -nostrend
+		rxwinup
+		txdata -datalen 16384 -nostrend
+		rxwinup
+		txdata -datalen 16384 -nostrend
+		rxwinup
+		txdata -datalen 16384 -nostrend
+		rxwinup
+		txdata -datalen 16384
+		rxresp
+		expect resp.status == 200
+	} -start
+} -run