--- sylpheed/libsylph/quoted-printable.c.alt-qpfix	2005-09-13 12:18:44 +0400

+++ sylpheed/libsylph/quoted-printable.c	2006-05-21 22:01:00 +0400

@@ -142,6 +142,28 @@ gint qp_decode_q_encoding(guchar *out, c

 	return outp - out;

 }

+/**

+ * Check if the character can be represented directly in a Q-encoded word.

+ *

+ * @param	c	Tested character

+ *

+ * @returns	1 if the character can be represented directly, 0 if it must be

+ * 		hex-encoded.

+ *

+ * @warning	The argument is evaluated multiple times.

+ *

+ * @note	This macro uses the most restrictive set of allowed characters

+ * 		(described in RFC 2047, section 5, (3)), so the word encoded

+ * 		according to these rules should be usable in all contexts where

+ * 		an encoded word may appear.

+ */

+#define IS_QP_SAFE_CHAR(c)					\

+	( ((c) >= 'A' && (c) <= 'Z') ||				\

+	  ((c) >= 'a' && (c) <= 'z') ||				\

+	  ((c) >= '0' && (c) <= '9') ||				\

+	  ((c) == '!') || ((c) == '*') || ((c) == '+') ||	\

+	  ((c) == '-') || ((c) == '/') )

+

 gint qp_get_q_encoding_len(const guchar *str)

 {

 	const guchar *inp = str;

@@ -150,11 +172,10 @@ gint qp_get_q_encoding_len(const guchar 

 	while (*inp != '\0') {

 		if (*inp == 0x20)

 			len++;

-		else if (*inp == '=' || *inp == '?' || *inp == '_' ||

-			 *inp < 32 || *inp > 127 || g_ascii_isspace(*inp))

-			len += 3;

-		else

+		else if (IS_QP_SAFE_CHAR(*inp))

 			len++;

+		else

+			len += 3;

 		inp++;

 	}

@@ -170,13 +191,13 @@ void qp_q_encode(gchar *out, const gucha

 	while (*inp != '\0') {

 		if (*inp == 0x20)

 			*outp++ = '_';

-		else if (*inp == '=' || *inp == '?' || *inp == '_' ||

-			 *inp < 32 || *inp > 127 || g_ascii_isspace(*inp)) {

+		else if (IS_QP_SAFE_CHAR(*inp))

+			*outp++ = *inp;

+		else {

 			*outp++ = '=';

 			get_hex_str(outp, *inp);

 			outp += 2;

-		} else

-			*outp++ = *inp;

+		}

 		inp++;

 	}