[evolution] Bug 610741 - Allow changing the abbreviated date (%ad) date format

[Milan Crha <mcrha src gnome org>]

commit a4fbe506aeb67c720e8aaab661ff4638e0f030f3
Author: Milan Crha <mcrha redhat com>
Date:   Fri Oct 19 12:53:35 2018 +0200

    Bug 610741 - Allow changing the abbreviated date (%ad) date format
    
    Closes https://bugzilla.gnome.org/show_bug.cgi?id=610741

 src/e-util/e-datetime-format.c | 28 +++++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 5 deletions(-)
---
diff --git a/src/e-util/e-datetime-format.c b/src/e-util/e-datetime-format.c
index 185c37a8f7..9f8a06d6f1 100644
--- a/src/e-util/e-datetime-format.c
+++ b/src/e-util/e-datetime-format.c
@@ -180,10 +180,11 @@ set_format_internal (const gchar *key,
 static gchar *
 format_relative_date (time_t tvalue,
                       time_t ttoday,
+                     const gchar *prefer_date_fmt,
                       const struct tm *value,
                       const struct tm *today)
 {
-       gchar *res = g_strdup (get_default_format (DTFormatKindDate, NULL));
+       gchar *res = g_strdup (prefer_date_fmt ? prefer_date_fmt : get_default_format (DTFormatKindDate, 
NULL));
        GDate now, val;
        gint diff;
 
@@ -303,9 +304,10 @@ format_internal (const gchar *key,
                        if (fmt[i + 1] == '%') {
                                i++;
                        } else if (fmt[i + 1] == 'a' && fmt[i + 2] == 'd' && (fmt[i + 3] == 0 || 
!g_ascii_isalpha (fmt[i + 3]))) {
-                               gchar *ad;
+                               gchar *ad, *prefer_date_fmt = NULL;
 
-                               /* "%ad" for abbreviated date */
+                               /* "%ad" for abbreviated date; it can be optionally extended
+                                  with preferred date format in [], like this: "%ad[%Y-%m-%d]" */
                                if (!use_fmt) {
                                        use_fmt = g_string_new ("");
 
@@ -317,12 +319,28 @@ format_internal (const gchar *key,
                                last = i + 3;
                                i += 2;
 
-                               ad = format_relative_date (tvalue, ttoday, &value, &today);
+                               if (fmt[i + 1] == '[' && fmt[i + 2] != ']') {
+                                       const gchar *end;
+
+                                       end = strchr (fmt + i + 1, ']');
+                                       if (end) {
+                                               gint len = end - fmt - i - 1;
+
+                                               prefer_date_fmt = g_strndup (fmt + i + 2, len - 1);
+
+                                               /* Include the ending ']' */
+                                               last += len + 1;
+                                               i += len + 1;
+                                       }
+                               }
+
+                               ad = format_relative_date (tvalue, ttoday, prefer_date_fmt, &value, &today);
                                if (ad)
                                        g_string_append (use_fmt, ad);
-                               else if (g_ascii_isspace (fmt[i + 3]))
+                               else if (g_ascii_isspace (fmt[i + 1]))
                                        i++;
 
+                               g_free (prefer_date_fmt);
                                g_free (ad);
                        }
                }