Fix URLs in CSV exports

This includes the instance's hostname in calls to export a CSV file and
PublicPost.CanonicalURL().

It also fixes a panic in that method during CSV export caused by draft
posts.

account.go

@@ -625,7 +625,7 @@ func viewExportPosts(app *App, w http.ResponseWriter, r *http.Request) ([]byte,
 
 	// Export as CSV
 	if strings.HasSuffix(r.URL.Path, ".csv") {
-		data = exportPostsCSV(u, posts)
+		data = exportPostsCSV(app.cfg.App.Host, u, posts)
 		return data, filename, err
 	}
 	if strings.HasSuffix(r.URL.Path, ".zip") {

export.go

@@ -20,7 +20,7 @@ import (
 	"github.com/writeas/web-core/log"
 )
 
-func exportPostsCSV(u *User, posts *[]PublicPost) []byte {
+func exportPostsCSV(hostName string, u *User, posts *[]PublicPost) []byte {
 	var b bytes.Buffer
 
 	r := [][]string{
@@ -30,8 +30,9 @@ func exportPostsCSV(u *User, posts *[]PublicPost) []byte {
 		var blog string
 		if p.Collection != nil {
 			blog = p.Collection.Alias
+			p.Collection.hostName = hostName
 		}
-		f := []string{p.ID, p.Slug.String, blog, p.CanonicalURL(), p.Created8601(), p.Title.String, strings.Replace(p.Content, "\n", "\\n", -1)}
+		f := []string{p.ID, p.Slug.String, blog, p.CanonicalURL(hostName), p.Created8601(), p.Title.String, strings.Replace(p.Content, "\n", "\\n", -1)}
 		r = append(r, f)
 	}
 

posts.go

@@ -1061,9 +1061,9 @@ func (p *Post) processPost() PublicPost {
 	return *res
 }
 
-func (p *PublicPost) CanonicalURL() string {
+func (p *PublicPost) CanonicalURL(hostName string) string {
 	if p.Collection == nil || p.Collection.Alias == "" {
-		return p.Collection.hostName + "/" + p.ID
+		return hostName + "/" + p.ID
 	}
 	return p.Collection.CanonicalURL() + p.Slug.String
 }
@@ -1072,7 +1072,7 @@ func (p *PublicPost) ActivityObject(cfg *config.Config) *activitystreams.Object
 	o := activitystreams.NewArticleObject()
 	o.ID = p.Collection.FederatedAPIBase() + "api/posts/" + p.ID
 	o.Published = p.Created
-	o.URL = p.CanonicalURL()
+	o.URL = p.CanonicalURL(cfg.App.Host)
 	o.AttributedTo = p.Collection.FederatedAccount()
 	o.CC = []string{
 		p.Collection.FederatedAccount() + "/followers",

read.go

@@ -293,7 +293,7 @@ func viewLocalTimelineFeed(app *App, w http.ResponseWriter, req *http.Request) e
 		}
 
 		title = p.PlainDisplayTitle()
-		permalink = p.CanonicalURL()
+		permalink = p.CanonicalURL(app.cfg.App.Host)
 		if p.Collection != nil {
 			author = p.Collection.Title
 		} else {