From: Rob Pike <r@golang.org>
Date: Thu, 13 Jun 2024 23:48:09 +0000 (+1000)
Subject: text/template/parse: fix handling of assignment/declaration in PipeNode.String
X-Git-Tag: go1.23rc2~2^2~65
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=6fea4094242fe4e7be8bd7ec0b55df9f6df3f025;p=gostls13.git

text/template/parse: fix handling of assignment/declaration in PipeNode.String

The String method for Pipes assumed all variables were declared. Easy fix:
check the IsAssign bit.

Fixes #65382

Change-Id: I58f2760c1a8bb2821c3538645d893f58fd76ae73
Reviewed-on: https://go-review.googlesource.com/c/go/+/592695
Run-TryBot: Rob Pike <r@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Rob Pike <r@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
---

diff --git a/src/text/template/parse/node.go b/src/text/template/parse/node.go
index 23ba9aec2b..a31309874d 100644
--- a/src/text/template/parse/node.go
+++ b/src/text/template/parse/node.go
@@ -217,7 +217,11 @@ func (p *PipeNode) writeTo(sb *strings.Builder) {
 			}
 			v.writeTo(sb)
 		}
-		sb.WriteString(" := ")
+		if p.IsAssign {
+			sb.WriteString(" = ")
+		} else {
+			sb.WriteString(" := ")
+		}
 	}
 	for i, c := range p.Cmds {
 		if i > 0 {
diff --git a/src/text/template/parse/parse_test.go b/src/text/template/parse/parse_test.go
index faf226d1c3..26aff330fe 100644
--- a/src/text/template/parse/parse_test.go
+++ b/src/text/template/parse/parse_test.go
@@ -306,6 +306,9 @@ var parseTests = []parseTest{
 	{"bug1a", "{{$x:=.}}{{$x!2}}", hasError, ""},                     // ! is just illegal here.
 	{"bug1b", "{{$x:=.}}{{$x+2}}", hasError, ""},                     // $x+2 should not parse as ($x) (+2).
 	{"bug1c", "{{$x:=.}}{{$x +2}}", noError, "{{$x := .}}{{$x +2}}"}, // It's OK with a space.
+	// Check the range handles assignment vs. declaration properly.
+	{"bug2a", "{{range $x := 0}}{{$x}}{{end}}", noError, "{{range $x := 0}}{{$x}}{{end}}"},
+	{"bug2b", "{{range $x = 0}}{{$x}}{{end}}", noError, "{{range $x = 0}}{{$x}}{{end}}"},
 	// dot following a literal value
 	{"dot after integer", "{{1.E}}", hasError, ""},
 	{"dot after float", "{{0.1.E}}", hasError, ""},