libfdisk: allocate enough bytes for ucs2 to utf8 encoding

Allocate 3*number_of_ucs2_characters bytes for utf8 output.

Also as we are using calloc there's no need to write terminating null
byte.

Signed-off-by: Vaclav Dolezal <vdolezal@redhat.com>

1 files changed, 6 insertions, 7 deletions

diff --git a/libfdisk/src/gpt.c b/libfdisk/src/gpt.c
index d77ed2d2b..8598dbd2e 100644
--- a/libfdisk/src/gpt.c
+++ b/libfdisk/src/gpt.c
@@ -1634,9 +1634,10 @@ static char *encode_to_utf8(unsigned char *src, size_t count)
 {
 	uint16_t c;
 	char *dest;
-	size_t i, j, len = count;
+	size_t i, j;
+	size_t len = count * 3 / 2;
 
-	dest = calloc(1, count);
+	dest = calloc(1, len + 1);
 	if (!dest)
 		return NULL;
 
@@ -1644,26 +1645,24 @@ static char *encode_to_utf8(unsigned char *src, size_t count)
 		/* always little endian */
 		c = (src[i+1] << 8) | src[i];
 		if (c == 0) {
-			dest[j] = '\0';
 			break;
 		} else if (c < 0x80) {
-			if (j+1 >= len)
+			if (j+1 > len)
 				break;
 			dest[j++] = (uint8_t) c;
 		} else if (c < 0x800) {
-			if (j+2 >= len)
+			if (j+2 > len)
 				break;
 			dest[j++] = (uint8_t) (0xc0 | (c >> 6));
 			dest[j++] = (uint8_t) (0x80 | (c & 0x3f));
 		} else {
-			if (j+3 >= len)
+			if (j+3 > len)
 				break;
 			dest[j++] = (uint8_t) (0xe0 | (c >> 12));
 			dest[j++] = (uint8_t) (0x80 | ((c >> 6) & 0x3f));
 			dest[j++] = (uint8_t) (0x80 | (c & 0x3f));
 		}
 	}
-	dest[j] = '\0';
 
 	return dest;
 }