1 files changed, 70 insertions, 0 deletions
diff --git a/lesstest/wchar.c b/lesstest/wchar.c
new file mode 100644
index 000000000000..7e0e3fb8b976
--- /dev/null
+++ b/lesstest/wchar.c
@@ -0,0 +1,70 @@
+#include <unistd.h>
+#include "lt_types.h"
+
+// Return number of bytes in the UTF-8 sequence which begins with a given byte.
+int wchar_len(byte b) {
+	if ((b & 0xE0) == 0xC0) return 2;
+	if ((b & 0xF0) == 0xE0) return 3;
+	if ((b & 0xF8) == 0xF0) return 4;
+	return 1;
+}
+
+void store_wchar(byte** p, wchar ch) {
+	if (ch < 0x80) {
+		*(*p)++ = (char) ch;
+	} else if (ch < 0x800) {
+		*(*p)++ = (byte) (0xC0 | ((ch >> 6) & 0x1F));
+		*(*p)++ = (byte) (0x80 | (ch & 0x3F));
+	} else if (ch < 0x10000) {
+		*(*p)++ = (byte) (0xE0 | ((ch >> 12) & 0x0F));
+		*(*p)++ = (byte) (0x80 | ((ch >> 6) & 0x3F));
+		*(*p)++ = (byte) (0x80 | (ch & 0x3F));
+	} else {
+		*(*p)++ = (byte) (0xF0 | ((ch >> 18) & 0x07));
+		*(*p)++ = (byte) (0x80 | ((ch >> 12) & 0x3F));
+		*(*p)++ = (byte) (0x80 | ((ch >> 6) & 0x3F));
+		*(*p)++ = (byte) (0x80 | (ch & 0x3F));
+	}
+}
+
+wchar load_wchar(const byte** p) {
+	wchar ch;
+	switch (wchar_len(**p)) {
+	default:
+		ch = *(*p)++ & 0xFF;
+		break;
+	case 2:
+		ch = (*(*p)++ & 0x1F) << 6;
+		ch |= *(*p)++ & 0x3F;
+		break;
+	case 3:
+		ch = (*(*p)++ & 0x0F) << 12;
+		ch |= (*(*p)++ & 0x3F) << 6;
+		ch |= (*(*p)++ & 0x3F);
+		break;
+	case 4:
+		ch = (*(*p)++ & 0x07) << 18;
+		ch |= (*(*p)++ & 0x3F) << 12;
+		ch |= (*(*p)++ & 0x3F) << 6;
+		ch |= (*(*p)++ & 0x3F);
+		break;
+	}
+	return ch;
+}
+
+wchar read_wchar(int fd) {
+	byte cbuf[UNICODE_MAX_BYTES];
+	int n = read(fd, &cbuf[0], 1);
+	if (n <= 0)
+		return 0;
+	int len = wchar_len(cbuf[0]);
+	int i;
+	for (i = 1; i < len; ++i) {
+		int n = read(fd, &cbuf[i], 1);
+		if (n != 1) return 0;
+	}
+	const byte* cp = cbuf;
+	wchar ch = load_wchar(&cp);
+	// assert(cp-cbuf == len);
+	return ch;
+}