[glib/wip/carlosg/gdatetime-before-y1000: 1/2] glib: Format GDateTime ISO8601 years as %C%y

[Carlos Garnacho <carlosg src gnome org>]

commit b48cb29bcb6e19a06c67b4b29f41120348a7c912
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sun Mar 20 13:22:38 2022 +0100

    glib: Format GDateTime ISO8601 years as %C%y
    
    The current use of %Y does not take into account that %Y will
    not pad the year with 0's, meanwhile ISO8601 does expect a full
    YYYY format for all dates. This breaks the formatting with dates
    prior to the year 1000.
    
    Split this into %C%y so 2-digit, 0-padded century and year are
    printed separately, this gives the expected YYYY format.

 glib/gdatetime.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/glib/gdatetime.c b/glib/gdatetime.c
index 429cadefc..6299cdb11 100644
--- a/glib/gdatetime.c
+++ b/glib/gdatetime.c
@@ -3492,12 +3492,12 @@ g_date_time_format_iso8601 (GDateTime *datetime)
   GString *outstr = NULL;
   gchar *main_date = NULL;
   gint64 offset;
-  gchar *format = "%Y-%m-%dT%H:%M:%S";
+  gchar *format = "%C%y-%m-%dT%H:%M:%S";
 
   /* if datetime has sub-second non-zero values below the second precision we
    * should print them as well */
   if (datetime->usec % G_TIME_SPAN_SECOND != 0)
-    format = "%Y-%m-%dT%H:%M:%S.%f";
+    format = "%C%y-%m-%dT%H:%M:%S.%f";
 
   /* Main date and time. */
   main_date = g_date_time_format (datetime, format);