[fractal] roomhistory: fix date format in day divider

[Daniel Garcia Moreno <danigm src gnome org>]

commit 13ccd74276fc574255c89a67c1633b8be8110a01
Author: Julian Sparber <julian sparber net>
Date:   Sat Dec 22 22:56:22 2018 +0100

    roomhistory: fix date format in day divider

 fractal-gtk/src/widgets/room_history.rs | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)
---
diff --git a/fractal-gtk/src/widgets/room_history.rs b/fractal-gtk/src/widgets/room_history.rs
index 6f28a86..1d9ce16 100644
--- a/fractal-gtk/src/widgets/room_history.rs
+++ b/fractal-gtk/src/widgets/room_history.rs
@@ -1,6 +1,7 @@
 use chrono::DateTime;
 use chrono::Datelike;
 use chrono::Local;
+use chrono::Timelike;
 use std::cell::RefCell;
 use std::collections::VecDeque;
 use std::rc::Rc;
@@ -283,11 +284,27 @@ fn should_group_message(msg: &MessageContent, prev: &MessageContent) -> bool {
 
 /* Create the day divider */
 fn create_day_divider(date: DateTime<Local>) -> gtk::ListBoxRow {
+    let gdate = glib::DateTime::new_local(
+        date.year(),
+        date.month() as i32,
+        date.day() as i32,
+        date.hour() as i32,
+        date.minute() as i32,
+        date.second() as f64,
+    );
     /* We show the year only when the message wasn't send in the current year */
-    let stamp = if date.year() == Local::now().year() {
-        date.format(i18n("%e %B").as_str()).to_string()
+    let format = if date.year() == Local::now().year() {
+        // Translators: This is a date format in the day divider without the year
+        i18n("%B %e")
     } else {
-        date.format(i18n("%e %B %Y").as_str()).to_string()
+        // Translators: This is a date format in the day divider with the year
+        i18n("%B %e, %Y")
+    };
+    let stamp = if let Some(string) = gdate.format(&format) {
+        string
+    } else {
+        // Fallback to a non glib time string
+        date.format(&format).to_string()
     };
     let row = gtk::ListBoxRow::new();
     if let Some(style) = row.get_style_context() {