ref: d15fda500028c05fde2aa28ea53868eec01140f6
parent: 7d5c9fbf44ad9f2fd5baed405f79f2b132dd9178
author: Cameron Moore <[email protected]>
date: Tue Mar 29 16:50:54 EDT 2016
tpl: Fix panic in pairList.Less While sorting on data sources with missing fields, a panic can occur in pairList.Less if `Interface()` is called on a invalid `reflect.Value`. This commit detects an invalid Value and replacing it with a zero value for the comparison.
--- a/tpl/template_funcs.go
+++ b/tpl/template_funcs.go
@@ -1054,7 +1054,24 @@
func (p pairList) Swap(i, j int) { p.Pairs[i], p.Pairs[j] = p.Pairs[j], p.Pairs[i] } func (p pairList) Len() int { return len(p.Pairs) } func (p pairList) Less(i, j int) bool {- return lt(p.Pairs[i].SortByValue.Interface(), p.Pairs[j].SortByValue.Interface())
+ iv := p.Pairs[i].SortByValue
+ jv := p.Pairs[j].SortByValue
+
+ if iv.IsValid() {+ if jv.IsValid() {+ // can only call Interface() on valid reflect Values
+ return lt(iv.Interface(), jv.Interface())
+ }
+ // if j is invalid, test i against i's zero value
+ return lt(iv.Interface(), reflect.Zero(iv.Type()))
+ }
+
+ if jv.IsValid() {+ // if i is invalid, test j against j's zero value
+ return lt(reflect.Zero(jv.Type()), jv.Interface())
+ }
+
+ return false
}
// sorts a pairList and returns a slice of sorted values
--- a/tpl/template_funcs_test.go
+++ b/tpl/template_funcs_test.go
@@ -1535,6 +1535,21 @@
"asc",
[]map[string]mid{{"foo": mid{Tst: TstX{A: "a", B: "b"}}}, {"foo": mid{Tst: TstX{A: "c", B: "d"}}}, {"foo": mid{Tst: TstX{A: "e", B: "f"}}}},},
+ // interface slice with missing elements
+ {+ []interface{}{+ map[interface{}]interface{}{"Title": "Foo", "Weight": 10},+ map[interface{}]interface{}{"Title": "Bar"},+ map[interface{}]interface{}{"Title": "Zap", "Weight": 5},+ },
+ "Weight",
+ "asc",
+ []interface{}{+ map[interface{}]interface{}{"Title": "Bar"},+ map[interface{}]interface{}{"Title": "Zap", "Weight": 5},+ map[interface{}]interface{}{"Title": "Foo", "Weight": 10},+ },
+ },
// test error cases
{(*[]TstX)(nil), nil, "asc", false}, {TstX{A: "a", B: "b"}, nil, "asc", false},