volume_id: code shrink

function                                             old     new   delta
volume_id_set_unicode16                              200     173     -27

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 19 insertions, 15 deletions

diff --git a/util-linux/volume_id/util.c b/util-linux/volume_id/util.c
index dd75c7ba1..69e43dda8 100644
--- a/util-linux/volume_id/util.c
+++ b/util-linux/volume_id/util.c
@@ -31,25 +31,29 @@ void volume_id_set_unicode16(char *str, size_t len, const uint8_t *buf, enum end
                         c = (buf[i+1] << 8) | buf[i];
                 else
                         c = (buf[i] << 8) | buf[i+1];
-                if (c == 0) {
-                        str[j] = '\0';
+                if (c == 0)
                         break;
-                } else if (c < 0x80) {
-                        if (j+1 >= len)
-                                break;
-                        str[j++] = (uint8_t) c;
-                } else if (c < 0x800) {
-                        if (j+2 >= len)
-                                break;
-                        str[j++] = (uint8_t) (0xc0 | (c >> 6));
-                        str[j++] = (uint8_t) (0x80 | (c & 0x3f));
+                if (j+1 >= len)
+                        break;
+                if (c < 0x80) {
+                        /* 0xxxxxxx */
                 } else {
-                        if (j+3 >= len)
+                        uint8_t topbits = 0xc0;
+                        if (j+2 >= len)
                                 break;
-                        str[j++] = (uint8_t) (0xe0 | (c >> 12));
-                        str[j++] = (uint8_t) (0x80 | ((c >> 6) & 0x3f));
-                        str[j++] = (uint8_t) (0x80 | (c & 0x3f));
+                        if (c < 0x800) {
+                                /* 110yyyxx 10xxxxxx */
+                        } else {
+                                if (j+3 >= len)
+                                        break;
+                                /* 1110yyyy 10yyyyxx 10xxxxxx */
+                                str[j++] = (uint8_t) (0xe0 | (c >> 12));
+                                topbits = 0x80;
+                        }
+                        str[j++] = (uint8_t) (topbits | ((c >> 6) & 0x3f));
+                        c = 0x80 | (c & 0x3f);
                 }
+                str[j++] = (uint8_t) c;
         }
         str[j] = '\0';
 }