text/template/parse: specify slice capacity in Pipenode.CopyPipe()

The required vars slice capacity is known so it can be specified before appending.

Change-Id: Ifa2fe97602e84198c4d01e5a1b0529f3f65f2df1
GitHub-Last-Rev: a0580df208a1d498968138d63508ae4e30df2ec5
GitHub-Pull-Request: golang/go#34613
Reviewed-on: https://go-review.googlesource.com/c/go/+/197997
Reviewed-by: Andrew Bonventre <andybons@golang.org>

diff --git a/src/text/template/parse/node.go b/src/text/template/parse/node.go
index 1174a4b970673ae6e4936e1def036238a45d46a6..74552c293f70fec1b9c7d1fa92712076430f1553 100644 (file)
--- a/src/text/template/parse/node.go
+++ b/src/text/template/parse/node.go
@@ -187,7 +187,7 @@ func (p *PipeNode) CopyPipe() *PipeNode {
        if p == nil {
                return p
        }
-       var vars []*VariableNode
+       vars := make([]*VariableNode, 0, len(p.Decl))
        for _, d := range p.Decl {
                vars = append(vars, d.Copy().(*VariableNode))
        }