From eafe86c2df73c9d80d2eab17b0c50ed8514cba81 Mon Sep 17 00:00:00 2001
From: Anthony Martin <ality@pbrane.org>
Date: Mon, 27 Feb 2012 13:56:43 -0800
Subject: [PATCH] go/printer: fix printing of variadic function calls

Fixes #3130.

R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/5697062
---
 src/pkg/go/printer/nodes.go                   |  7 +++++-
 .../go/printer/testdata/expressions.golden    | 22 +++++++++++++++++++
 src/pkg/go/printer/testdata/expressions.input | 22 +++++++++++++++++++
 src/pkg/go/printer/testdata/expressions.raw   | 22 +++++++++++++++++++
 4 files changed, 72 insertions(+), 1 deletion(-)

diff --git a/src/pkg/go/printer/nodes.go b/src/pkg/go/printer/nodes.go
index cd5e075c16c..2205f633f1d 100644
--- a/src/pkg/go/printer/nodes.go
+++ b/src/pkg/go/printer/nodes.go
@@ -804,9 +804,14 @@ func (p *printer) expr1(expr ast.Expr, prec1, depth int, multiLine *bool) {
 		}
 		p.expr1(x.Fun, token.HighestPrec, depth, multiLine)
 		p.print(x.Lparen, token.LPAREN)
-		p.exprList(x.Lparen, x.Args, depth, commaSep|commaTerm, multiLine, x.Rparen)
 		if x.Ellipsis.IsValid() {
+			p.exprList(x.Lparen, x.Args, depth, commaSep, multiLine, x.Ellipsis)
 			p.print(x.Ellipsis, token.ELLIPSIS)
+			if x.Rparen.IsValid() && p.lineFor(x.Ellipsis) < p.lineFor(x.Rparen) {
+				p.print(token.COMMA, formfeed)
+			}
+		} else {
+			p.exprList(x.Lparen, x.Args, depth, commaSep|commaTerm, multiLine, x.Rparen)
 		}
 		p.print(x.Rparen, token.RPAREN)
 
diff --git a/src/pkg/go/printer/testdata/expressions.golden b/src/pkg/go/printer/testdata/expressions.golden
index 95fdd95ffbb..45fa4d97a4a 100644
--- a/src/pkg/go/printer/testdata/expressions.golden
+++ b/src/pkg/go/printer/testdata/expressions.golden
@@ -625,3 +625,25 @@ func f() {
 		log.Fatal(err)
 	}
 }
+
+// Handle multi-line argument lists ending in ... correctly.
+// Was issue 3130.
+func _() {
+	_ = append(s, a...)
+	_ = append(
+		s, a...)
+	_ = append(s,
+		a...)
+	_ = append(
+		s,
+		a...)
+	_ = append(s, a...,
+	)
+	_ = append(s,
+		a...,
+	)
+	_ = append(
+		s,
+		a...,
+	)
+}
diff --git a/src/pkg/go/printer/testdata/expressions.input b/src/pkg/go/printer/testdata/expressions.input
index d1131498352..f545c66057c 100644
--- a/src/pkg/go/printer/testdata/expressions.input
+++ b/src/pkg/go/printer/testdata/expressions.input
@@ -654,3 +654,25 @@ func f() {
 	    log.Fatal(err)
 	}
 }
+
+// Handle multi-line argument lists ending in ... correctly.
+// Was issue 3130.
+func _() {
+	_ = append(s, a...)
+	_ = append(
+		s, a...)
+	_ = append(s,
+		a...)
+	_ = append(
+		s,
+		a...)
+	_ = append(s, a...,
+	)
+	_ = append(s,
+		a...,
+	)
+	_ = append(
+		s,
+		a...,
+	)
+}
diff --git a/src/pkg/go/printer/testdata/expressions.raw b/src/pkg/go/printer/testdata/expressions.raw
index 3442ba9b950..87a4b00836d 100644
--- a/src/pkg/go/printer/testdata/expressions.raw
+++ b/src/pkg/go/printer/testdata/expressions.raw
@@ -625,3 +625,25 @@ func f() {
 		log.Fatal(err)
 	}
 }
+
+// Handle multi-line argument lists ending in ... correctly.
+// Was issue 3130.
+func _() {
+	_ = append(s, a...)
+	_ = append(
+		s, a...)
+	_ = append(s,
+		a...)
+	_ = append(
+		s,
+		a...)
+	_ = append(s, a...,
+	)
+	_ = append(s,
+		a...,
+	)
+	_ = append(
+		s,
+		a...,
+	)
+}