Prevent panic in Context.GetQuery() when there is no Request (#2412)

Co-authored-by: thinkerou <thinkerou@gmail.com>

context.go

@@ -416,7 +416,11 @@ func (c *Context) QueryArray(key string) []string {
 
 func (c *Context) initQueryCache() {
 	if c.queryCache == nil {
-		c.queryCache = c.Request.URL.Query()
+		if c.Request != nil {
+			c.queryCache = c.Request.URL.Query()
+		} else {
+			c.queryCache = url.Values{}
+		}
 	}
 }
 

context_test.go

@@ -410,6 +410,21 @@ func TestContextQuery(t *testing.T) {
 	assert.Empty(t, c.PostForm("foo"))
 }
 
+func TestContextDefaultQueryOnEmptyRequest(t *testing.T) {
+	c, _ := CreateTestContext(httptest.NewRecorder()) // here c.Request == nil
+	assert.NotPanics(t, func() {
+		value, ok := c.GetQuery("NoKey")
+		assert.False(t, ok)
+		assert.Empty(t, value)
+	})
+	assert.NotPanics(t, func() {
+		assert.Equal(t, "nada", c.DefaultQuery("NoKey", "nada"))
+	})
+	assert.NotPanics(t, func() {
+		assert.Empty(t, c.Query("NoKey"))
+	})
+}
+
 func TestContextQueryAndPostForm(t *testing.T) {
 	c, _ := CreateTestContext(httptest.NewRecorder())
 	body := bytes.NewBufferString("foo=bar&page=11&both=&foo=second")