Don't create the public folder unless needed

Fixes #11031

hugofs/fs.go

@@ -116,13 +116,9 @@ func newFs(source, destination afero.Fs, workingDir, publishDir string) *Fs {
 		panic("workingDir is too short")
 	}
 
+	// If this does not exist, it will be created later.
 	absPublishDir := paths.AbsPathify(workingDir, publishDir)
 
-	// Make sure we always have the /public folder ready to use.
-	if err := source.MkdirAll(absPublishDir, 0777); err != nil && !os.IsExist(err) {
-		panic(err)
-	}
-
 	pubFs := afero.NewBasePathFs(destination, absPublishDir)
 
 	return &Fs{

main_test.go

@@ -132,6 +132,11 @@ var commonTestScriptsParam = testscript.Params{
 			if err != nil {
 				ts.Fatalf("%v", err)
 			}
+			if len(fis) == 0 {
+				// To simplify empty dir checks.
+				fmt.Fprintln(ts.Stdout(), "Empty dir")
+				return
+			}
 			for _, fi := range fis {
 				fmt.Fprintf(ts.Stdout(), "%s %04o %s %s\n", fi.Mode(), fi.Mode().Perm(), fi.ModTime().Format(time.RFC3339Nano), fi.Name())
 			}

testscripts/commands/hugo__noconfig.txt

@@ -1,4 +1,8 @@
 
+mkdir mysite
+cd mysite
 ! hugo
 
-stderr 'Unable to locate config file or config directory'
+stderr 'Unable to locate config file or config directory'
+ls .
+stdout 'Empty dir'