Do not panic on index out of range in shortcode.Get

Fixes #1335

diff --git a/hugolib/shortcode.go b/hugolib/shortcode.go
index ac1a7f1d3d7e3153d28b78409cf0866019fa99ec..8b445f0db2e6acbc4dbfb263b1f1da6819e86852 100644 (file)
--- a/hugolib/shortcode.go
+++ b/hugolib/shortcode.go
@@ -60,7 +60,13 @@ func (scp *ShortcodeWithPage) Get(key interface{}) interface{} {
                if reflect.TypeOf(scp.Params).Kind() == reflect.Map {
                        return "error: cannot access named params by position"
                } else if reflect.TypeOf(scp.Params).Kind() == reflect.Slice {
-                       x = reflect.ValueOf(scp.Params).Index(int(reflect.ValueOf(key).Int()))
+                       idx := int(reflect.ValueOf(key).Int())
+                       ln := reflect.ValueOf(scp.Params).Len()
+                       if idx > ln-1 {
+                               helpers.DistinctErrorLog.Printf("No shortcode param at .Get %d in page %s, have params: %v", idx, scp.Page.FullFilePath(), scp.Params)
+                               return fmt.Sprintf("error: index out of range for positional param at position %d", idx)
+                       }
+                       x = reflect.ValueOf(scp.Params).Index(idx)
                }
        case string:
                if reflect.TypeOf(scp.Params).Kind() == reflect.Map {

diff --git a/hugolib/shortcode_test.go b/hugolib/shortcode_test.go
index d7afbc14ebb93801ad7cedc4518ccafabf1c3c15..43c958aff6bfbc528558661d8e13a32c7c8e3d3d 100644 (file)
--- a/hugolib/shortcode_test.go
+++ b/hugolib/shortcode_test.go
@@ -85,6 +85,12 @@ func TestPositionalParamSC(t *testing.T) {
        CheckShortCodeMatch(t, "{{<   video   47238zzb    >}}", "Playing Video 47238zzb", tem)
 }
 
+func TestPositionalParamIndexOutOfBounds(t *testing.T) {
+       tem := tpl.New()
+       tem.AddInternalShortcode("video.html", `Playing Video {{ .Get 1 }}`)
+       CheckShortCodeMatch(t, "{{< video 47238zzb >}}", "Playing Video error: index out of range for positional param at position 1", tem)
+}
+
 func TestNamedParamSC(t *testing.T) {
        tem := tpl.New()
        tem.AddInternalShortcode("img.html", `<img{{ with .Get "src" }} src="{{.}}"{{end}}{{with .Get "class"}} class="{{.}}"{{end}}>`)