Ask querier for sorted series in /federate

Signed-off-by: darshanime <deathbullet@gmail.com>

web/federate.go

@@ -95,7 +95,7 @@ func (h *Handler) federation(w http.ResponseWriter, req *http.Request) {
 
 	var sets []storage.SeriesSet
 	for _, mset := range matcherSets {
-		s := q.Select(false, hints, mset...)
+		s := q.Select(true, hints, mset...)
 		sets = append(sets, s)
 	}
 

web/federate_test.go

@@ -113,6 +113,14 @@ test_metric1{foo="bar",instance="i"} 10000 6000000
 test_metric1{foo="boo",instance="i"} 1 6000000
 # TYPE test_metric2 untyped
 test_metric2{foo="boo",instance="i"} 1 6000000
+`,
+	},
+	"two matchers with overlap": {
+		params: "match[]={__name__=~'test_metric1'}&match[]={foo='bar'}",
+		code:   200,
+		body: `# TYPE test_metric1 untyped
+test_metric1{foo="bar",instance="i"} 10000 6000000
+test_metric1{foo="boo",instance="i"} 1 6000000
 `,
 	},
 	"everything": {