[PATCH] Reset req->err_code to zero when doing restart from vcl_fetch()

[Martin Blix Grydeland]

By resetting the req->err_code upon restarting after vcl_fetch(), a
proper 503 will be issued if this later triggers a max restarts error
instead of whatever status code the aborted backend connection
returned.

Test case by: scoof

Fixes: #1113
---
 bin/varnishd/cache/cache_center.c |    1 +
 bin/varnishtest/tests/r01113.vtc  |   21 +++++++++++++++++++++
 2 files changed, 22 insertions(+), 0 deletions(-)
 create mode 100644 bin/varnishtest/tests/r01113.vtc

diff --git a/bin/varnishd/cache/cache_center.c b/bin/varnishd/cache/cache_center.c
index 7104e0f..1fa8604 100644
--- a/bin/varnishd/cache/cache_center.c
+++ b/bin/varnishd/cache/cache_center.c
@@ -661,6 +661,7 @@ cnt_fetch(struct sess *sp, struct worker *wrk, struct req *req)
 	switch (req->handling) {
 	case VCL_RET_RESTART:
 		req->restarts++;
+		req->err_code = 0;
 		sp->step = STP_RECV;
 		return (0);
 	case VCL_RET_ERROR:
diff --git a/bin/varnishtest/tests/r01113.vtc b/bin/varnishtest/tests/r01113.vtc
new file mode 100644
index 0000000..efbfd55
--- /dev/null
+++ b/bin/varnishtest/tests/r01113.vtc
@@ -0,0 +1,21 @@
+varnishtest "HTTP status code when hitting max_restarts"
+
+server s1 {
+	rxreq
+	txresp
+	accept
+	rxreq
+	txresp
+} -start
+
+varnish v1 -vcl+backend {
+	sub vcl_fetch {
+		return(restart);
+	}
+} -start -cliok "param.set max_restarts 1"
+
+client c1 {
+	txreq
+	rxresp
+	expect resp.status == 503
+} -run
-- 
1.7.4.1