From cf1517a4dbdbbd6d2537c5bbf5732b6e335e9cdf Mon Sep 17 00:00:00 2001
From: Simon McVittie <smcv@collabora.com>
Date: Tue, 30 Aug 2022 18:49:54 +0100
Subject: [PATCH] uri: Don't rely on g_time_zone_new_offset()

g_time_zone_new_offset() was new in GLib 2.58, but Ubuntu 18.04 'bionic'
only has GLib 2.56, and in theory we still claim to support versions
all the way back to GLib 2.46. If that function isn't available,
reimplement it in terms of the deprecated g_time_zone_new().

Signed-off-by: Simon McVittie <smcv@collabora.com>
(cherry picked from commit 3591ba08f673bcfb99c8da4fa3c6960cf5e776b7)
---
 common/flatpak-uri.c | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/common/flatpak-uri.c b/common/flatpak-uri.c
index c66e56c1..7ec6606e 100644
--- a/common/flatpak-uri.c
+++ b/common/flatpak-uri.c
@@ -1614,6 +1614,41 @@ parse_time (int *hour, int *minute, int *second, const char **date_string)
   return TRUE;
 }
 
+static inline GTimeZone *
+time_zone_new_offset (gint32 offset)
+{
+#if GLIB_CHECK_VERSION (2, 58, 0)
+  return g_time_zone_new_offset (offset);
+#else
+  g_autofree char *id = NULL;
+  gint hours, minutes;
+  gint seconds = offset;
+  GTimeZone *tz;
+  char sign = '+';
+
+  if (seconds == 0)
+    return g_time_zone_new_utc ();
+
+  if (seconds < 0)
+    {
+      seconds = -seconds;
+      sign = '-';
+    }
+
+  hours = seconds / 3600;
+  seconds = seconds % 3600;
+  minutes = seconds / 60;
+  seconds = seconds % 60;
+
+  id = g_strdup_printf ("%c%02d:%02d:%02d", sign, hours, minutes, seconds);
+  tz = g_time_zone_new (id);
+  /* If this assertion fails, we'll log a critical but still return tz,
+   * which is documented to be UTC if the time zone could not be parsed */
+  g_return_val_if_fail (g_time_zone_get_offset (tz, 0) == offset, tz);
+  return tz;
+#endif
+}
+
 static inline gboolean
 parse_timezone (GTimeZone **timezone_out, const char **date_string)
 {
@@ -1664,7 +1699,7 @@ parse_timezone (GTimeZone **timezone_out, const char **date_string)
   if (utc)
     *timezone_out = g_time_zone_new_utc ();
   else
-    *timezone_out = g_time_zone_new_offset (offset_minutes * 60);
+    *timezone_out = time_zone_new_offset (offset_minutes * 60);
 
   return TRUE;
 }