gzip: Allow empty extension (#509)

caddy/setup/gzip.go

@@ -47,7 +47,7 @@ func gzipParse(c *Controller) ([]gzip.Config, error) {
 					return configs, c.ArgErr()
 				}
 				for _, e := range exts {
-					if !strings.HasPrefix(e, ".") && e != gzip.ExtWildCard {
+					if !strings.HasPrefix(e, ".") && e != gzip.ExtWildCard && e != "" {
 						return configs, fmt.Errorf(`gzip: invalid extension "%v" (must start with dot)`, e)
 					}
 					extFilter.Exts.Add(e)

caddy/setup/gzip_test.go

@@ -50,6 +50,9 @@ func TestGzip(t *testing.T) {
 		 level 1
 		}
 		gzip`, false},
+		{`gzip {
+		 ext ""
+		}`, false},
 		{`gzip { not /file
 		 ext .html
 		 level 1