Propagate StrictSlash to subrouters instead of rudely turning it off

regexp.go

@@ -98,12 +98,13 @@ func newRouteRegexp(tpl string, matchHost, matchPrefix, strictSlash bool) (*rout
 	}
 	// Done!
 	return &routeRegexp{
-		template:  template,
-		matchHost: matchHost,
-		regexp:    reg,
-		reverse:   reverse.String(),
-		varsN:     varsN,
-		varsR:     varsR,
+		template:    template,
+		matchHost:   matchHost,
+		strictSlash: strictSlash,
+		regexp:      reg,
+		reverse:     reverse.String(),
+		varsN:       varsN,
+		varsR:       varsR,
 	}, nil
 }
 
@@ -114,6 +115,8 @@ type routeRegexp struct {
 	template string
 	// True for host match, false for path match.
 	matchHost bool
+	// The strictSlash value defined on the route, but disabled if PathPrefix was used.
+	strictSlash bool
 	// Expanded regexp.
 	regexp *regexp.Regexp
 	// Reverse template.
@@ -216,7 +219,7 @@ func (v *routeRegexpGroup) setMatch(req *http.Request, m *RouteMatch, r *Route)
 				m.Vars[v] = pathVars[k+1]
 			}
 			// Check if we should redirect.
-			if r.strictSlash {
+			if v.path.strictSlash {
 				p1 := strings.HasSuffix(req.URL.Path, "/")
 				p2 := strings.HasSuffix(v.path.template, "/")
 				if p1 != p2 {