6 files changed, 59 insertions, 6 deletions
diff --git a/hugolib/hugo_sites.go b/hugolib/hugo_sites.go
index e71e48d41..ee0d5c563 100644
--- a/hugolib/hugo_sites.go
+++ b/hugolib/hugo_sites.go
@@ -49,6 +49,7 @@ import (
 
 	"github.com/gohugoio/hugo/langs/i18n"
 	"github.com/gohugoio/hugo/resources/page"
+	"github.com/gohugoio/hugo/resources/page/pagemeta"
 	"github.com/gohugoio/hugo/tpl"
 	"github.com/gohugoio/hugo/tpl/tplimpl"
 )
@@ -690,7 +691,7 @@ func (cfg *BuildCfg) shouldRender(p *pageState) bool {
 	return false
 }
 
-func (h *HugoSites) renderCrossSitesArtifacts() error {
+func (h *HugoSites) renderCrossSitesSitemap() error {
 
 	if !h.multilingual.enabled() || h.IsMultihost() {
 		return nil
@@ -716,6 +717,38 @@ func (h *HugoSites) renderCrossSitesArtifacts() error {
 		s.siteCfg.sitemap.Filename, h.toSiteInfos(), templ)
 }
 
+func (h *HugoSites) renderCrossSitesRobotsTXT() error {
+	if h.multihost {
+		return nil
+	}
+	if !h.Cfg.GetBool("enableRobotsTXT") {
+		return nil
+	}
+
+	s := h.Sites[0]
+
+	p, err := newPageStandalone(&pageMeta{
+		s:    s,
+		kind: kindRobotsTXT,
+		urlPaths: pagemeta.URLPath{
+			URL: "robots.txt",
+		},
+	},
+		output.RobotsTxtFormat)
+
+	if err != nil {
+		return err
+	}
+
+	if !p.render {
+		return nil
+	}
+
+	templ := s.lookupLayouts("robots.txt", "_default/robots.txt", "_internal/_default/robots.txt")
+
+	return s.renderAndWritePage(&s.PathSpec.ProcessingStats.Pages, "Robots Txt", "robots.txt", p, templ)
+}
+
 func (h *HugoSites) removePageByFilename(filename string) {
 	h.getContentMaps().withMaps(func(m *pageMap) error {
 		m.deleteBundleMatching(func(b *contentNode) bool {
diff --git a/hugolib/hugo_sites_build.go b/hugolib/hugo_sites_build.go
index f39e7a7e5..67ee10e09 100644
--- a/hugolib/hugo_sites_build.go
+++ b/hugolib/hugo_sites_build.go
@@ -334,7 +334,10 @@ func (h *HugoSites) render(config *BuildCfg) error {
 	}
 
 	if !config.SkipRender {
-		if err := h.renderCrossSitesArtifacts(); err != nil {
+		if err := h.renderCrossSitesSitemap(); err != nil {
+			return err
+		}
+		if err := h.renderCrossSitesRobotsTXT(); err != nil {
 			return err
 		}
 	}
diff --git a/hugolib/hugo_sites_build_test.go b/hugolib/hugo_sites_build_test.go
index 84655c1f2..8d0872bd5 100644
--- a/hugolib/hugo_sites_build_test.go
+++ b/hugolib/hugo_sites_build_test.go
@@ -255,8 +255,10 @@ func doTestMultiSitesBuild(t *testing.T, configTemplate, configSuffix string) {
 	b.AssertFileContent("public/fr/404.html", "404|fr|404 Page not found")
 
 	// Check robots.txt
-	b.AssertFileContent("public/en/robots.txt", "robots|en|")
-	b.AssertFileContent("public/nn/robots.txt", "robots|nn|")
+	// the domain root is the public directory, so the robots.txt has to be created there and not in the language directories
+	b.AssertFileContent("public/robots.txt", "robots")
+	b.AssertFileDoesNotExist("public/en/robots.txt")
+	b.AssertFileDoesNotExist("public/nn/robots.txt")
 
 	b.AssertFileContent("public/en/sect/doc1-slug/index.html", "Permalink: http://example.com/blog/en/sect/doc1-slug/")
 	b.AssertFileContent("public/en/sect/doc2/index.html", "Permalink: http://example.com/blog/en/sect/doc2/")
diff --git a/hugolib/hugo_sites_multihost_test.go b/hugolib/hugo_sites_multihost_test.go
index a15e8cd43..4fe496042 100644
--- a/hugolib/hugo_sites_multihost_test.go
+++ b/hugolib/hugo_sites_multihost_test.go
@@ -19,6 +19,7 @@ disablePathToLower = true
 defaultContentLanguage = "fr"
 defaultContentLanguageInSubdir = false
 staticDir = ["s1", "s2"]
+enableRobotsTXT = true
 
 [permalinks]
 other = "/somewhere/else/:filename"
@@ -73,6 +74,12 @@ languageName = "Nynorsk"
 	c.Assert(pageWithURLInFrontMatter.RelPermalink(), qt.Equals, "/docs/superbob/")
 	b.AssertFileContent("public/en/superbob/index.html", "doc3|Hello|en")
 
+	// the domain root is the language directory for each language, so the robots.txt is created in the language directories
+	b.AssertFileContent("public/en/robots.txt", "robots|en")
+	b.AssertFileContent("public/fr/robots.txt", "robots|fr")
+	b.AssertFileContent("public/nn/robots.txt", "robots|nn")
+	b.AssertFileDoesNotExist("public/robots.txt")
+
 	// check alias:
 	b.AssertFileContent("public/en/al/alias1/index.html", `content="0; url=https://example.com/docs/superbob/"`)
 	b.AssertFileContent("public/en/al/alias2/index.html", `content="0; url=https://example.com/docs/superbob/"`)
diff --git a/hugolib/site.go b/hugolib/site.go
index 5507d7a78..ac65931d0 100644
--- a/hugolib/site.go
+++ b/hugolib/site.go
@@ -1209,8 +1209,10 @@ func (s *Site) render(ctx *siteRenderContext) (err error) {
 			return
 		}
 
-		if err = s.renderRobotsTXT(); err != nil {
-			return
+		if ctx.multihost {
+			if err = s.renderRobotsTXT(); err != nil {
+				return
+			}
 		}
 
 		if err = s.render404(); err != nil {
diff --git a/hugolib/testhelpers_test.go b/hugolib/testhelpers_test.go
index c1ee27557..2af4691d1 100644
--- a/hugolib/testhelpers_test.go
+++ b/hugolib/testhelpers_test.go
@@ -726,6 +726,12 @@ func (s *sitesBuilder) AssertFileContent(filename string, matches ...string) {
 	}
 }
 
+func (s *sitesBuilder) AssertFileDoesNotExist(filename string) {
+	if s.CheckExists(filename) {
+		s.Fatalf("File %q exists but must not exist.", filename)
+	}
+}
+
 func (s *sitesBuilder) AssertImage(width, height int, filename string) {
 	filename = filepath.Join(s.workingDir, filename)
 	f, err := s.Fs.Destination.Open(filename)