Keep trailing slash when baseUrl contains a sub path

Before this commit, .Site.BaseUrl ended up as:

http://mysite.com/ => http://mysite.com/
http://mysite.com/sub/ => http://mysite.com/sub

Now it becomes:

http://mysite.com/ => http://mysite.com/
http://mysite.com/sub/ => http://mysite.com/sub/

Fixed gohugoio#931

helpers/url.go

@@ -52,9 +52,8 @@ func (PathBridge) Separator() string {
 
 var pathBridge PathBridge
 
-// SanitizeUrl sanitizes the input URL string.
-func SanitizeUrl(in string) string {
-	s, err := purell.NormalizeURLString(in, purell.FlagsSafe|purell.FlagRemoveTrailingSlash|purell.FlagRemoveDotSegments|purell.FlagRemoveDuplicateSlashes|purell.FlagRemoveUnnecessaryHostDots|purell.FlagRemoveEmptyPortSeparator)
+func sanitizeUrlWithFlags(in string, f purell.NormalizationFlags) string {
+	s, err := purell.NormalizeURLString(in, f)
 	if err != nil {
 		return in
 	}
@@ -85,6 +84,17 @@ func SanitizeUrl(in string) string {
 	// End temporary kludge
 
 	//return s
+
+}
+
+// SanitizeUrl sanitizes the input URL string.
+func SanitizeUrl(in string) string {
+	return sanitizeUrlWithFlags(in, purell.FlagsSafe|purell.FlagRemoveTrailingSlash|purell.FlagRemoveDotSegments|purell.FlagRemoveDuplicateSlashes|purell.FlagRemoveUnnecessaryHostDots|purell.FlagRemoveEmptyPortSeparator)
+}
+
+// SanitizeUrlKeepTrailingSlash is the same as SanitizeUrl, but will keep any trailing slash.
+func SanitizeUrlKeepTrailingSlash(in string) string {
+	return sanitizeUrlWithFlags(in, purell.FlagsSafe|purell.FlagRemoveDotSegments|purell.FlagRemoveDuplicateSlashes|purell.FlagRemoveUnnecessaryHostDots|purell.FlagRemoveEmptyPortSeparator)
 }
 
 // Similar to MakePath, but with Unicode handling

helpers/url_test.go

@@ -1,9 +1,9 @@
 package helpers
 
 import (
-	"testing"
-
 	"github.com/stretchr/testify/assert"
+	"strings"
+	"testing"
 )
 
 func TestUrlize(t *testing.T) {
@@ -26,6 +26,34 @@ func TestUrlize(t *testing.T) {
 	}
 }
 
+func TestSanitizeUrl(t *testing.T) {
+	tests := []struct {
+		input    string
+		expected string
+	}{
+		{"http://foo.bar/", "http://foo.bar/"},
+		{"http://foo.bar/zoo/", "http://foo.bar/zoo"}, // issue #931
+	}
+
+	for _, test := range tests {
+		o1 := SanitizeUrl(test.input)
+		o2 := SanitizeUrlKeepTrailingSlash(test.input)
+
+		expected2 := test.expected
+
+		if strings.HasSuffix(test.input, "/") && !strings.HasSuffix(expected2, "/") {
+			expected2 += "/"
+		}
+
+		if o1 != test.expected {
+			t.Errorf("Expected %#v, got %#v\n", test.expected, o1)
+		}
+		if o2 != expected2 {
+			t.Errorf("Expected %#v, got %#v\n", expected2, o2)
+		}
+	}
+}
+
 func TestMakePermalink(t *testing.T) {
 	type test struct {
 		host, link, output string

hugolib/site.go

@@ -444,7 +444,7 @@ func (s *Site) initializeSiteInfo() {
 	}
 
 	s.Info = SiteInfo{
-		BaseUrl:         template.URL(helpers.SanitizeUrl(viper.GetString("BaseUrl"))),
+		BaseUrl:         template.URL(helpers.SanitizeUrlKeepTrailingSlash(viper.GetString("BaseUrl"))),
 		Title:           viper.GetString("Title"),
 		Author:          viper.GetStringMap("author"),
 		LanguageCode:    viper.GetString("languagecode"),