1 files changed, 97 insertions, 0 deletions
diff --git a/vendor/nunicode/src/libnu/utf8.c b/vendor/nunicode/src/libnu/utf8.c
new file mode 100644
index 0000000000..c9ea0fc819
--- /dev/null
+++ b/vendor/nunicode/src/libnu/utf8.c
@@ -0,0 +1,97 @@
+#include <libnu/utf8.h>
+
+#ifdef NU_WITH_UTF8_READER
+#ifdef NU_WITH_VALIDATION
+
+int nu_utf8_validread(const char *encoded, size_t max_len) {
+	int len = utf8_validread_basic(encoded, max_len);
+
+	if (len <= 0) {
+		return 0;
+	}
+
+	/* Unicode core spec, D92, Table 3-7
+	 */
+
+	switch (len) {
+	/* case 1: single byte sequence can't be > 0x7F and produce len == 1
+	 */
+
+	case 2: {
+		uint8_t p1 = *(const unsigned char *)(encoded);
+
+		if (p1 < 0xC2) { /* 2-byte sequences with p1 > 0xDF are 3-byte sequences */
+			return 0;
+		}
+
+		/* the rest will be handled by utf8_validread_basic() */
+
+		break;
+	}
+
+	case 3: {
+		uint8_t p1 = *(const unsigned char *)(encoded);
+
+		/* 3-byte sequences with p1 < 0xE0 are 2-byte sequences,
+		 * 3-byte sequences with p1 > 0xEF are 4-byte sequences */
+
+		uint8_t p2 = *(const unsigned char *)(encoded + 1);
+
+		if (p1 == 0xE0 && p2 < 0xA0) {
+			return 0;
+		}
+		else if (p1 == 0xED && p2 > 0x9F) {
+			return 0;
+		}
+
+		/* (p2 < 0x80 || p2 > 0xBF) and p3 will be covered
+		 * by utf8_validread_basic() */
+
+		break;
+	}
+
+	case 4: {
+		uint8_t p1 = *(const unsigned char *)(encoded);
+
+		if (p1 > 0xF4) { /* 4-byte sequence with p1 < 0xF0 are 3-byte sequences */
+			return 0;
+		}
+
+		uint8_t p2 = *(const unsigned char *)(encoded + 1);
+
+		if (p1 == 0xF0 && p2 < 0x90) {
+			return 0;
+		}
+
+		/* (p2 < 0x80 || p2 > 0xBF) and the rest (p3, p4)
+		 * will be covered by utf8_validread_basic() */
+
+		break;
+	}
+
+	} /* switch */
+
+	return len;
+}
+
+#endif /* NU_WITH_VALIDATION */
+#endif /* NU_WITH_UTF8_READER */
+
+#ifdef NU_WITH_UTF8_WRITER
+
+char* nu_utf8_write(uint32_t unicode, char *utf8) {
+	unsigned codepoint_len = utf8_codepoint_length(unicode);
+
+	if (utf8 != 0) {
+		switch (codepoint_len) {
+			case 1: *utf8 = (char)(unicode); break;
+			case 2: b2_utf8(unicode, utf8); break;
+			case 3: b3_utf8(unicode, utf8); break;
+			default: b4_utf8(unicode, utf8); break; /* len == 4 */
+		}
+	}
+
+	return utf8 + codepoint_len;
+}
+
+#endif /* NU_WITH_UTF8_WRITER */