fixes a crash on systems that dont have utf7 in iconv.

2002-08-28  Not Zed  <NotZed@Ximian.com>

        * providers/imap/camel-imap-utils.c (imap_mailbox_encode): Chagned
        to use camel_utf8_utf7 code.
        (imap_mailbox_decode): As above, using camel_utf8_utf7.  'UTF-7'
        isn't a widely support iconv() codeset, and besides the new code
        is simpler.

        * camel-utf8.[ch]: robust utilities for working with utf8 and utf7.

svn path=/trunk/; revision=17886

1 files changed, 257 insertions, 0 deletions

diff --git a/camel/camel-utf8.c b/camel/camel-utf8.c
new file mode 100644
index 0000000000..5ed5a476d0
--- /dev/null
+++ b/camel/camel-utf8.c
@@ -0,0 +1,257 @@
+
+#include <glib.h>
+#include "camel-utf8.h"
+
+/**
+ * camel_utf8_putc:
+ * @ptr: 
+ * @c: 
+ * 
+ * Output a 32 bit unicode character as utf8 octets.  At most 4 octets will
+ * be written to @ptr.  @ptr will be advanced to the next character position.
+ **/
+void
+camel_utf8_putc(unsigned char **ptr, guint32 c)
+{
+	register unsigned char *p = *ptr;
+
+	if (c <= 0x7f)
+		*p++ = c;
+	else if (c <= 0x7ff) {
+		*p++ = 0xc0 | c >> 6;
+		*p++ = 0x80 | (c & 0x3f);
+	} else if (c <= 0xffff) {
+		*p++ = 0xe0 | c >> 12;
+		*p++ = 0x80 | ((c >> 6) & 0x3f);
+		*p++ = 0x80 | (c & 0x3f);
+	} else {
+		/* see unicode standard 3.0, S 3.8, max 4 octets */
+		*p++ = 0xf0 | c >> 18;
+		*p++ = 0x80 | ((c >> 12) & 0x3f);
+		*p++ = 0x80 | ((c >> 6) & 0x3f);
+		*p++ = 0x80 | (c & 0x3f);
+	}
+
+	*ptr = p;
+}
+
+/**
+ * camel_utf8_getc:
+ * @ptr: 
+ * 
+ * Get a Unicode character from a utf8 stream.  @ptr will be advanced
+ * to the next character position.  Invalid utf8 characters will be
+ * silently skipped.  @ptr should point to a NUL terminated array.
+ * 
+ * Return value: The next Unicode character.  @ptr will be advanced to
+ * the next character always.
+ **/
+guint32
+camel_utf8_getc(const unsigned char **ptr)
+{
+	register unsigned char *p = (unsigned char *)*ptr;
+	register unsigned char c, r;
+	register guint32 v, m;
+
+again:
+	r = *p++;
+loop:
+	if (r < 0x80) {
+		*ptr = p;
+		v = r;
+	} else if (r < 0xf8) { /* valid start char? (max 4 octets) */
+		v = r;
+		m = 0x7f80;	/* used to mask out the length bits */
+		do {
+			c = *p++;
+			if ((c & 0xc0) != 0x80) {
+				r = c;
+				goto loop;
+			}
+			v = (v<<6) | (c & 0x3f);
+			r<<=1;
+			m<<=5;
+		} while (r & 0x40);
+		
+		*ptr = p;
+
+		v &= ~m;
+	} else {
+		goto again;
+	}
+
+	return v;
+}
+
+void
+g_string_append_u(GString *out, guint32 c)
+{
+	unsigned char buffer[8];
+	unsigned char *p = buffer;
+
+	camel_utf8_putc(&p, c);
+	*p = 0;
+	g_string_append(out, buffer);
+}
+
+static char *utf7_alphabet =
+	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,";
+
+static unsigned char utf7_rank[256] = {
+	0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+	0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+	0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0x3e,0x3f,0xff,0xff,0xff,
+	0x34,0x35,0x36,0x37,0x38,0x39,0x3a,0x3b,0x3c,0x3d,0xff,0xff,0xff,0xff,0xff,0xff,
+	0xff,0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,
+	0x0f,0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0xff,0xff,0xff,0xff,0xff,
+	0xff,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f,0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,0x28,
+	0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f,0x30,0x31,0x32,0x33,0xff,0xff,0xff,0xff,0xff,
+	0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+	0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+	0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+	0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+	0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+	0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+	0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+	0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+};
+
+/**
+ * camel_utf7_utf8:
+ * @ptr: 
+ * 
+ * Convert a modified utf7 string to utf8.  If the utf7 string
+ * contains 8 bit characters, they are treated as iso-8859-1.
+ * 
+ * The IMAP rules [rfc2060] are used in the utf7 encoding.
+ *
+ * Return value: The converted string.
+ **/
+char *
+camel_utf7_utf8(const char *ptr)
+{
+	const unsigned char *p = (unsigned char *)ptr;
+	unsigned int c;
+	guint32 v=0, x;
+	GString *out;
+	int i=0;
+	int state = 0;
+	char *ret;
+
+	out = g_string_new("");
+	do {
+		c = *p++;
+		switch(state) {
+		case 0:
+			if (c == '&')
+				state = 1;
+			else
+				g_string_append_u(out, c);
+			break;
+		case 1:
+			if (c == '-') {
+				g_string_append_c(out, '&');
+				state = 0;
+			} else if (utf7_rank[c] != 0xff) {
+				v = utf7_rank[c];
+				i = 6;
+				state = 2;
+			} else {
+				/* invalid */
+				g_string_append(out, "&-");
+				state = 0;
+			}
+			break;
+		case 2:
+			if (c == '-') {
+				state = 0;
+			} else if (utf7_rank[c] != 0xff) {
+				v = (v<<6) | utf7_rank[c];
+				i+=6;
+				if (i >= 16) {
+					x = (v >> (i-16)) & 0xffff;
+					g_string_append_u(out, x);
+					i-=16;
+				}
+			} else {
+				g_string_append_u(out, c);
+				state = 0;
+			}
+			break;
+		}
+	} while (c);
+
+	ret = g_strdup(out->str);
+	g_string_free(out, TRUE);
+
+	return ret;
+}
+
+static void utf7_closeb64(GString *out, guint32 v, guint32 i)
+{
+	guint32 x;
+
+	if (i>0) {
+		x = (v << (6-i)) & 0x3f;
+		g_string_append_c(out, utf7_alphabet[x]);
+	}
+	g_string_append_c(out, '-');
+}
+
+/**
+ * camel_utf8_utf7:
+ * @ptr: 
+ * 
+ * Convert a utf8 string to a modified utf7 format.
+ *
+ * The IMAP rules [rfc2060] are used in the utf7 encoding.
+ * 
+ * Return value: 
+ **/
+char *
+camel_utf8_utf7(const char *ptr)
+{
+	const unsigned char *p = (unsigned char *)ptr;
+	unsigned int c;
+	guint32 x, v = 0;
+	int state = 0;
+	GString *out;
+	int i = 0;
+	char *ret;
+
+	out = g_string_new("");
+
+	while ( (c = camel_utf8_getc(&p)) ) {
+		if (c >= 0x20 && c <= 0x7e) {
+			if (state == 1) {
+				utf7_closeb64(out, v, i);
+				state = 0;
+				i = 0;
+			}
+			if (c == '&')
+				g_string_append(out, "&-");
+			else
+				g_string_append_c(out, c);
+		} else {
+			if (state == 0) {
+				g_string_append_c(out, '&');
+				state = 1;
+			}
+			v = (v << 16) | c;
+			i += 16;
+			while (i >= 6) {
+				x = (v >> (i-6)) & 0x3f;
+				g_string_append_c(out, utf7_alphabet[x]);
+				i -= 6;
+			}
+		}
+	}
+
+	if (state == 1)
+		utf7_closeb64(out, v, i);
+
+	ret = g_strdup(out->str);
+	g_string_free(out, TRUE);
+
+	return ret;
+}