notes: move hex_to_bytes() to hex.c and export it

Make the function for converting pairs of hexadecimal digits to binary
available to other call sites.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

cache.h

@@ -1317,6 +1317,13 @@ extern int set_disambiguate_hint_config(const char *var, const char *value);
 extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 extern int get_oid_hex(const char *hex, struct object_id *sha1);
 
+/*
+ * Read `len` pairs of hexadecimal digits from `hex` and write the
+ * values to `binary` as `len` bytes. Return 0 on success, or -1 if
+ * the input does not consist of hex digits).
+ */
+extern int hex_to_bytes(unsigned char *binary, const char *hex, size_t len);
+
 /*
  * Convert a binary sha1 to its hex equivalent. The `_r` variant is reentrant,
  * and writes the NUL-terminated output to the buffer `out`, which must be at

hex.c

@@ -35,6 +35,18 @@ const signed char hexval_table[256] = {
 	 -1, -1, -1, -1, -1, -1, -1, -1,		/* f8-ff */
 };
 
+int hex_to_bytes(unsigned char *binary, const char *hex, size_t len)
+{
+	for (; len; len--, hex += 2) {
+		unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
+
+		if (val & ~0xff)
+			return -1;
+		*binary++ = val;
+	}
+	return 0;
+}
+
 int get_sha1_hex(const char *hex, unsigned char *sha1)
 {
 	int i;

notes.c

@@ -334,23 +334,6 @@ static void note_tree_free(struct int_node *tree)
 	}
 }
 
-/*
- * Read `len` pairs of hexadecimal digits from `hex` and write the
- * values to `binary` as `len` bytes. Return 0 on success, or -1 if
- * the input does not consist of hex digits).
- */
-static int hex_to_bytes(unsigned char *binary, const char *hex, size_t len)
-{
-	for (; len; len--, hex += 2) {
-		unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
-
-		if (val & ~0xff)
-			return -1;
-		*binary++ = val;
-	}
-	return 0;
-}
-
 static int non_note_cmp(const struct non_note *a, const struct non_note *b)
 {
 	return strcmp(a->path, b->path);