[evolution] Busy-loop when printing specifically formatted HTML message

[Milan Crha <mcrha src gnome org>]

commit 76e9eec339633264d07d5af793ed3c71527aca6d
Author: Milan Crha <mcrha redhat com>
Date:   Mon Jul 4 12:27:21 2016 +0200

    Busy-loop when printing specifically formatted HTML message
    
    This had been reported at
    https://bugzilla.redhat.com/show_bug.cgi?id=1352271

 em-format/e-mail-formatter-text-html.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/em-format/e-mail-formatter-text-html.c b/em-format/e-mail-formatter-text-html.c
index 147af5d..7f4a81c 100644
--- a/em-format/e-mail-formatter-text-html.c
+++ b/em-format/e-mail-formatter-text-html.c
@@ -56,11 +56,13 @@ get_tag (const gchar *utf8_string,
 
        c = '\0';
        t = g_utf8_find_prev_char (utf8_string, closing);
-       while (t != opening) {
+       while (t && t > opening) {
 
                c = g_utf8_get_char (t);
                if (!g_unichar_isspace (c))
                        break;
+
+               t = g_utf8_find_prev_char (utf8_string, t);
        }
 
        /* Not a pair tag */