diff --git a/controller/crud.go b/controller/crud.go
index feaeef45..04facb2c 100644
--- a/controller/crud.go
+++ b/controller/crud.go
@@ -660,9 +660,9 @@ func (c *Controller) cmdSet(msg *server.Message) (res string, d commandDetailsT,
 		col = collection.New()
 		c.setCol(d.key, col)
 	}
-	if nx {
+	if xx || nx {
 		_, _, ok := col.Get(d.id)
-		if ok {
+		if (nx && ok) || (xx && !ok) {
 			goto notok
 		}
 	}
@@ -691,7 +691,12 @@ notok:
 	switch msg.OutputType {
 	default:
 	case server.JSON:
-		res = `{"ok":false,"elapsed":"` + time.Now().Sub(start).String() + "\"}"
+		if nx {
+			err = errIDAlreadyExists
+		} else {
+			err = errIDNotFound
+		}
+		return
 	case server.RESP:
 		res = "$-1\r\n"
 	}
diff --git a/controller/glob/glob.go b/controller/glob/glob.go
index 696214a7..72eb9a7f 100644
--- a/controller/glob/glob.go
+++ b/controller/glob/glob.go
@@ -1,5 +1,7 @@
 package glob
 
+import "strings"
+
 type Glob struct {
 	Pattern string
 	Desc    bool
@@ -24,7 +26,7 @@ func IsGlob(pattern string) bool {
 
 func Parse(pattern string, desc bool) *Glob {
 	g := &Glob{Pattern: pattern, Desc: desc, Limits: []string{"", ""}}
-	if pattern == "*" {
+	if strings.HasPrefix(pattern, "*") {
 		g.IsGlob = true
 		return g
 	}
diff --git a/controller/token.go b/controller/token.go
index 39cfa58a..5f0158dd 100644
--- a/controller/token.go
+++ b/controller/token.go
@@ -15,6 +15,7 @@ const defaultSearchOutput = outputObjects
 var errInvalidNumberOfArguments = errors.New("invalid number of arguments")
 var errKeyNotFound = errors.New("key not found")
 var errIDNotFound = errors.New("id not found")
+var errIDAlreadyExists = errors.New("id already exists")
 
 func errInvalidArgument(arg string) error {
 	return fmt.Errorf("invalid argument '%s'", arg)
diff --git a/docker/README.md b/docker/README.md
index 33487c89..11e1062b 100644
--- a/docker/README.md
+++ b/docker/README.md
@@ -1,4 +1,4 @@
-![Tile38 Logo](https://github.com/tidwall/tile38/blob/master/doc/logo200.png)
+![Tile38 Logo](https://raw.githubusercontent.com/tidwall/tile38/master/doc/logo200.png)
 
 Tile38 is an open source (MIT licensed), in-memory geolocation data store, spatial index, and realtime geofence. It supports a variety of object types including lat/lon points, bounding boxes, XYZ tiles, Geohashes, and GeoJSON.