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| author | Bjørn Erik Pedersen <bjorn.erik.pedersen@gmail.com> | 2017-07-08 11:31:09 +0300 |
|---|---|---|
| committer | Bjørn Erik Pedersen <bjorn.erik.pedersen@gmail.com> | 2017-07-08 11:31:09 +0300 |
| commit | dbbc5c4810a04ac06fad7500d88cf5c3bfe0c7fd (patch) | |
| tree | e9008c433e03b05344dbcbf0ffa8cdd6a2d24f49 /tpl | |
| parent | 7bcc1ce659710f2220b400ce3b76e50d2e48b241 (diff) | |
tpl/collections: Fix union when the first slice is empty
Fixes #3686
Diffstat (limited to 'tpl')
| -rw-r--r-- | tpl/collections/collections.go | 9 | ||||
| -rw-r--r-- | tpl/collections/collections_test.go | 7 |
2 files changed, 16 insertions, 0 deletions
diff --git a/tpl/collections/collections.go b/tpl/collections/collections.go index 103cb3860..bc80acbbe 100644 --- a/tpl/collections/collections.go +++ b/tpl/collections/collections.go @@ -494,6 +494,7 @@ type intersector struct { } func (i *intersector) appendIfNotSeen(v reflect.Value) { + vi := v.Interface() if !i.seen[vi] { i.r = reflect.Append(i.r, v) @@ -565,6 +566,14 @@ func (ns *Namespace) Union(l1, l2 interface{}) (interface{}, error) { } } + if !l1vv.IsValid() { + // The first slice may be empty. Pick the first value of the second + // to use as a prototype. + if l2v.Len() > 0 { + l1vv = l2v.Index(0) + } + } + for j := 0; j < l2v.Len(); j++ { l2vv := l2v.Index(j) diff --git a/tpl/collections/collections_test.go b/tpl/collections/collections_test.go index 46bef9483..239affad1 100644 --- a/tpl/collections/collections_test.go +++ b/tpl/collections/collections_test.go @@ -666,6 +666,13 @@ func TestUnion(t *testing.T) { {pagesVals{p1v}, pagesVals{p3v, p3v}, pagesVals{p1v, p3v}, false}, {[]interface{}{p1, p4}, []interface{}{p4, p2, p2}, []interface{}{p1, p4, p2}, false}, {[]interface{}{p1v}, []interface{}{p3v, p3v}, []interface{}{p1v, p3v}, false}, + // #3686 + {[]interface{}{p1v}, []interface{}{}, []interface{}{p1v}, false}, + {[]interface{}{}, []interface{}{p1v}, []interface{}{p1v}, false}, + {pagesPtr{p1}, pagesPtr{}, pagesPtr{p1}, false}, + {pagesVals{p1v}, pagesVals{}, pagesVals{p1v}, false}, + {pagesPtr{}, pagesPtr{p1}, pagesPtr{p1}, false}, + {pagesVals{}, pagesVals{p1v}, pagesVals{p1v}, false}, // errors {"not array or slice", []string{"a"}, false, true}, |