From 3a786a248d3eff6e732aa94e87d6e88196e5147a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B8rn=20Erik=20Pedersen?=
 <bjorn.erik.pedersen@gmail.com>
Date: Tue, 30 Oct 2018 17:36:05 +0100
Subject: [PATCH] tpl: Fix BOM issue in templates

Fixes #4895
---
 hugolib/template_test.go | 24 ++++++++++++++++++++++++
 tpl/tplimpl/template.go  | 19 ++++++++++++++++++-
 2 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/hugolib/template_test.go b/hugolib/template_test.go
index eed3ee8ed..9cc523cb0 100644
--- a/hugolib/template_test.go
+++ b/hugolib/template_test.go
@@ -212,3 +212,27 @@ Some content
 
 	}
 }
+
+// https://github.com/gohugoio/hugo/issues/4895
+func TestTemplateBOM(t *testing.T) {
+
+	b := newTestSitesBuilder(t).WithSimpleConfigFile()
+	bom := "\ufeff"
+
+	b.WithTemplatesAdded(
+		"_default/baseof.html", bom+`
+		Base: {{ block "main" . }}base main{{ end }}`,
+		"_default/single.html", bom+`{{ define "main" }}Hi!?{{ end }}`)
+
+	b.WithContent("page.md", `---
+title: "Page"
+---
+
+Page Content
+`)
+
+	b.CreateSites().Build(BuildCfg{})
+
+	b.AssertFileContent("public/page/index.html", "Base: Hi!?")
+
+}
diff --git a/tpl/tplimpl/template.go b/tpl/tplimpl/template.go
index 8a26ce0e1..144bafdd8 100644
--- a/tpl/tplimpl/template.go
+++ b/tpl/tplimpl/template.go
@@ -655,6 +655,22 @@ func (t *textTemplates) handleMaster(name, overlayFilename, masterFilename strin
 
 }
 
+func removeLeadingBOM(s string) string {
+	const bom = '\ufeff'
+
+	for i, r := range s {
+		if i == 0 && r != bom {
+			return s
+		}
+		if i > 0 {
+			return s[i:]
+		}
+	}
+
+	return s
+
+}
+
 func (t *templateHandler) addTemplateFile(name, baseTemplatePath, path string) error {
 	t.checkState()
 
@@ -666,7 +682,8 @@ func (t *templateHandler) addTemplateFile(name, baseTemplatePath, path string) e
 		if err != nil {
 			return templateInfo{filename: filename, fs: fs}, err
 		}
-		s := string(b)
+
+		s := removeLeadingBOM(string(b))
 
 		realFilename := filename
 		if fi, err := fs.Stat(filename); err == nil {