From 712b809316401c2e13339514430035a6b4a1b674 Mon Sep 17 00:00:00 2001
From: riacataquian <icataquian@gmail.com>
Date: Tue, 31 May 2022 19:30:24 +0800
Subject: [PATCH] syntax: fix whitespace on nested subshells

we want white space on nested subshells if its in a single line since
its ambiguous, eg we want `( (` over `((`

this shouldn't be the case for multiple lines- fix the logic that adds
white space to only do so if the two subshells are in the same line

fixes #814
---
 cmd/shfmt/in.sh        | 9 +++++++++
 syntax/printer.go      | 7 +++++++
 syntax/printer_test.go | 8 ++++++++
 3 files changed, 24 insertions(+)
 create mode 100644 cmd/shfmt/in.sh

diff --git a/cmd/shfmt/in.sh b/cmd/shfmt/in.sh
new file mode 100644
index 000000000..7a32449f6
--- /dev/null
+++ b/cmd/shfmt/in.sh
@@ -0,0 +1,9 @@
+#!/bin/bash
+
+# OK - no blank
+( (echo "Hello world!") )
+
+# nok - blank ^ after first (
+(
+	(echo "Hello world!")
+)
diff --git a/syntax/printer.go b/syntax/printer.go
index 7dc183a02..cbb310c83 100644
--- a/syntax/printer.go
+++ b/syntax/printer.go
@@ -1081,6 +1081,13 @@ func (p *Printer) command(cmd Command, redirs []*Redirect) (startRedirs int) {
 		p.WriteByte('(')
 		if len(x.Stmts) > 0 && startsWithLparen(x.Stmts[0]) {
 			p.wantSpace = spaceRequired
+			if nested, ok := x.Stmts[0].Cmd.(*Subshell); ok {
+				// we only want to keep the space between two nested subshells' open brackets
+				// if its in a single line to avoid ambiguity
+				if x.Lparen.Line() != nested.Pos().Line() {
+					p.wantSpace = spaceNotRequired
+				}
+			}
 		} else {
 			p.wantSpace = spaceNotRequired
 		}
diff --git a/syntax/printer_test.go b/syntax/printer_test.go
index 59483f689..4e12e6113 100644
--- a/syntax/printer_test.go
+++ b/syntax/printer_test.go
@@ -616,6 +616,14 @@ var printTests = []printCase{
 		"`declare`",
 		"$(declare)",
 	},
+	{
+		"(\n(foo >redir)\n)",
+		"(\n\t(foo >redir)\n)",
+	},
+	{
+		"( (foo >redir) )",
+		"( (foo >redir))",
+	},
 }
 
 func TestPrintWeirdFormat(t *testing.T) {