[evolution-data-server] Bug 752338 - Incorrect handling of multibyte characters in vCards

[Milan Crha <mcrha src gnome org>]

commit 1c662c95f650093abcf72b44be720de1fa34ab14
Author: Alex Shtyrov <alex shtyrov collabora co uk>
Date:   Wed Aug 5 17:30:57 2015 +0200

    Bug 752338 - Incorrect handling of multibyte characters in vCards

 addressbook/libebook-contacts/e-vcard.c |   27 +++++++++++++++++----------
 1 files changed, 17 insertions(+), 10 deletions(-)
---
diff --git a/addressbook/libebook-contacts/e-vcard.c b/addressbook/libebook-contacts/e-vcard.c
index e5c611b..9ff2298 100644
--- a/addressbook/libebook-contacts/e-vcard.c
+++ b/addressbook/libebook-contacts/e-vcard.c
@@ -334,30 +334,37 @@ read_attribute_value (EVCardAttribute *attr,
             lp = skip_newline ( lp, quoted_printable ) ) {
 
                if (*lp == '=' && quoted_printable) {
-                       gchar a, b;
+                       gunichar a, b;
 
                        /* it's for the '=' */
                        lp++;
                        lp = skip_newline (lp, quoted_printable);
 
-                       if ((a = *(lp++)) == '\0') break;
+                       a = g_utf8_get_char (lp);
+                       lp = g_utf8_next_char (lp);
+                       if (a == '\0')
+                               break;
+
                        lp = skip_newline (lp, quoted_printable);
 
-                       if ((b = *(lp++)) == '\0') break;
-                       if (isxdigit (a) && isxdigit (b)) {
+                       b = g_utf8_get_char (lp);
+                       if (b == '\0')
+                               break;
+                       lp = g_utf8_next_char (lp);
+
+                       if (g_unichar_isxdigit (a) && g_unichar_isxdigit (b)) {
                                gchar c;
 
-                               a = tolower (a);
-                               b = tolower (b);
+                               gint a_bin = g_unichar_xdigit_value (a);
+                               gint b_bin = g_unichar_xdigit_value (b);
 
-                               c = (((a >= 'a' ? a - 'a' + 10 : a - '0') & 0x0f) << 4)
-                                  | ((b >= 'a' ? b - 'a' + 10 : b - '0') & 0x0f);
+                               c = (a_bin << 4) | b_bin;
 
                                g_string_append_c (str, c); /* add decoded byte (this is not a unicode yet) */
                        } else {
                                g_string_append_c (str, '=');
-                               g_string_append_c (str, a);
-                               g_string_append_c (str, b);
+                               g_string_append_unichar (str, a);
+                               g_string_append_unichar (str, b);
                        }
                } else if (*lp == '\\') {
                        /* convert back to the non-escaped version of