[gnome-builder] gstyle: Fix alpha component . in some locales

[Sébastien Lafargue <slafargue src gnome org>]

commit 7474ecd98b7df8c8ea5f2d77eaf2df33f5e49fb5
Author: Sebastien Lafargue <slafargue gnome org>
Date:   Fri Aug 3 18:52:42 2018 +0200

    gstyle: Fix alpha component . in some locales
    
    Some locales were replacing it by a comma.

 src/gstyle/gstyle-color.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/src/gstyle/gstyle-color.c b/src/gstyle/gstyle-color.c
index 41710dfdc..abfc432f0 100644
--- a/src/gstyle/gstyle-color.c
+++ b/src/gstyle/gstyle-color.c
@@ -116,10 +116,13 @@ gstyle_color_to_hsla (GstyleColor *self,
 static gchar *
 truncate_trailing_zeros (gdouble number)
 {
-  gint c = g_snprintf(TRUNCATE_BUF, 6, "%.2f", number);
+  guint i = (guint)number;
+  guint f = (number - i) * 100;
+  gint c = g_snprintf (TRUNCATE_BUF, 5, "%d.%d", i, f);
 
+  /* Format the number string, e.g. "0.50" => "0.5"; "1.0" => "1" */
   --c;
-  while(TRUNCATE_BUF[c] == '0')
+  while (TRUNCATE_BUF[c] == '0')
     c--;
 
   if (TRUNCATE_BUF[c] == '.')