lib/ucs2_string: Correct ucs2 -> utf8 conversion

commit a68075908a37850918ad96b056acc9ac4ce1bd90 upstream.

The comparisons should be >= since 0x800 and 0x80 require an additional bit
to store.

For the 3 byte case, the existing shift would drop off 2 more bits than
intended.

For the 2 byte case, there should be 5 bits bits in byte 1, and 6 bits in
byte 2.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Matthew Garrett <mjg59@coreos.com>
Cc: "Lee, Chun-Yi" <jlee@suse.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/lib/ucs2_string.c b/lib/ucs2_string.c
index 17dd74e21ef93b2b2e97059bfa56b66c301a742c..f0b323abb4c64a566700d9d265f4451174847eaa 100644 (file)
--- a/lib/ucs2_string.c
+++ b/lib/ucs2_string.c
@@ -59,9 +59,9 @@ ucs2_utf8size(const ucs2_char_t *src)
        for (i = 0; i < ucs2_strlen(src); i++) {
                u16 c = src[i];
 
-               if (c > 0x800)
+               if (c >= 0x800)
                        j += 3;
-               else if (c > 0x80)
+               else if (c >= 0x80)
                        j += 2;
                else
                        j += 1;
@@ -88,19 +88,19 @@ ucs2_as_utf8(u8 *dest, const ucs2_char_t *src, unsigned long maxlength)
        for (i = 0; maxlength && i < limit; i++) {
                u16 c = src[i];
 
-               if (c > 0x800) {
+               if (c >= 0x800) {
                        if (maxlength < 3)
                                break;
                        maxlength -= 3;
                        dest[j++] = 0xe0 | (c & 0xf000) >> 12;
-                       dest[j++] = 0x80 | (c & 0x0fc0) >> 8;
+                       dest[j++] = 0x80 | (c & 0x0fc0) >> 6;
                        dest[j++] = 0x80 | (c & 0x003f);
-               } else if (c > 0x80) {
+               } else if (c >= 0x80) {
                        if (maxlength < 2)
                                break;
                        maxlength -= 2;
-                       dest[j++] = 0xc0 | (c & 0xfe0) >> 5;
-                       dest[j++] = 0x80 | (c & 0x01f);
+                       dest[j++] = 0xc0 | (c & 0x7c0) >> 6;
+                       dest[j++] = 0x80 | (c & 0x03f);
                } else {
                        maxlength -= 1;
                        dest[j++] = c & 0x7f;