test encode and decode

1 files changed, 33 insertions, 19 deletions

diff --git a/creole.c b/creole.c
index 58b6c83..3da1e3e 100644
--- a/creole.c
+++ b/creole.c
@@ -101,13 +101,15 @@ static int read_continue(struct creole_reader *r, struct word *w,
 
 	for (i = 0; i < to_read; i++) {
 		r_ret = read(r);
-		if (r_ret < 0)
+		if (r_ret < 0) {
 			return 0;
+		}
 		/* Characters might not be 8 bits! */
 		c = (unsigned char)(r_ret & 0xFF);
-		if (c >> 6 != 0x2)
+		if (c >> 6 != 0x2) {
 			return 0;
-		w->word = w->word << 6 | (c & 0x3F);
+		}
+		w->word = (w->word << 6) | (c & 0x3F);
 	}
 
 	return 1;
@@ -150,12 +152,12 @@ static int parse_start_byte(unsigned char c, struct word *w)
 		 */
 		int to_read;
 	} start_data[START_BYTE_NUM-1] = {
-		{0xFE, 0x00, 0, 0x0, 5}, /* 11111110 */
-		{0xFC, 0x00, 0, 0x1, 4}, /* 1111110x */
-		{0xF8, 0x00, 0, 0x3, 3}, /* 111110xx */
-		{0xF0, 0x00, 0, 0x7, 2}, /* 11110xxx */
-		{0xE0, 0x00, 0, 0xF, 2}, /* 1110xxxx */
-		{0xC0, 0x01, 1, 0xF, 1}  /* 110xxxxx */
+		{0xFE, 0x00, 0x0, 0, 5}, /* 11111110 */
+		{0xFC, 0x00, 0x1, 0, 4}, /* 1111110x */
+		{0xF8, 0x00, 0x3, 0, 3}, /* 111110xx */
+		{0xF0, 0x00, 0x7, 0, 2}, /* 11110xxx */
+		{0xE0, 0x00, 0xF, 0, 2}, /* 1110xxxx */
+		{0xC0, 0x01, 0xF, 1, 1}  /* 110xxxxx */
 	};
 
 	int i;
@@ -182,7 +184,7 @@ static int parse_start_byte(unsigned char c, struct word *w)
 
 /* This parses the first continuation byte if it is special. */
 #define SPECIAL_CONTINUE_BYTE_NUM (START_BYTE_NUM - 3)
-static void parse_special_byte(unsigned char c, struct word *w)
+static int parse_special_byte(unsigned char c, struct word *w)
 {
 	/* The index denotes the amount of high bits that were in
 	 * the start byte. This is the amount that the stored value
@@ -195,13 +197,22 @@ static void parse_special_byte(unsigned char c, struct word *w)
 	 * shifting the continue byte bits.
 	 */
 	static const unsigned char mask[SPECIAL_CONTINUE_BYTE_NUM] = {
-		0xF, /* 1111110 10HHHHxx */
-		0x7, /* 111110H 10HHHxxx */
-		0x3, /* 11110HH 10HHxxxx */
-		0x1  /* 1110HHH 10Hxxxxx */
+		0x1, /* 11110HHH 10Hxxxxx */
+		0x3, /* 111110HH 10HHxxxx */
+		0x7, /* 1111110H 10HHHxxx */
+		0xF  /* 11111110 10HHHHxx */
 	};
-	int i = w->len - START_BYTE_NUM;
-	w->high_bits = (w->high_bits << i) | ((c >> (2 + i)) & mask[i]);
+	static const unsigned char wordmask[SPECIAL_CONTINUE_BYTE_NUM] = {
+		0x1F, 0xF, 0x7, 0x3
+	};
+
+	int i = w->len - 4;
+	if (i >= SPECIAL_CONTINUE_BYTE_NUM)
+		return 0;
+
+	w->high_bits = (w->high_bits << i) | ((c >> (5 - i)) & mask[i]);
+	w->word = c & wordmask[i];
+	return 1;
 }
 
 /* Parse an entire Pseudo-UTF8 sequence. */
@@ -209,6 +220,7 @@ static int decode_seq(struct creole_reader *r, struct word *w)
 {
 	int r_ret;
 	int to_read;
+	w->high_bits = 0;
 
 	r_ret = read(r);
 	if (r_ret < 0)
@@ -225,7 +237,8 @@ static int decode_seq(struct creole_reader *r, struct word *w)
 		r_ret = read(r);
 		if (r_ret < 0)
 			return 0;
-		parse_special_byte((unsigned char)(r_ret & 0xFF), w);
+		if (!parse_special_byte((unsigned char)(r_ret & 0xFF), w))
+			return 0;
 	}
 
 	return read_continue(r, w, to_read);
@@ -252,7 +265,7 @@ int creole_encode(creole_word i, unsigned encode_to, unsigned high_bits,
 		{0x7FFFFFF,  0xFC, 3, 0, 27, 0x7, 3, 0x07}, /* 6 */
 		{0xFFFFFFFF, 0xFE, 4, 0, 32, 0xF, 2, 0x03}  /* 7 */
 	};
-	unsigned lb;
+	int lb;
 	unsigned j;
 
 	if (encode_to > 8)
@@ -267,8 +280,9 @@ int creole_encode(creole_word i, unsigned encode_to, unsigned high_bits,
 	}
 
 	lb = encode_to - 2;
-	if (i > d[lb].max)
+	if (i > d[lb].max) {
 		return 0;
+	}
 
 	buf[0] = (d[lb].b1_mask | (high_bits >> d[lb].high_bit_shift_b1
 	                           << d[lb].high_bit_shift_to_right_b1));