+
+ unsigned char const *src = read_buf;
+ unsigned char const *end = read_buf + s;
+ utf32 *dst = buf + MAX_PUTBACK;
+ utf32 decoded;
+ utf32 min_code;
+
+ if (part_decoded_rest_len != 0) {
+ min_code = part_decoded_min_code;
+ decoded = part_decoded_char;
+ size_t const rest_len = part_decoded_rest_len;
+ part_decoded_rest_len = 0;
+ switch (rest_len) {
+ case 4: goto realign;
+ case 3: goto three_more;
+ case 2: goto two_more;
+ default: goto one_more;
+ }
+ }
+
+ while (src != end) {
+ if ((*src & 0x80) == 0) {
+ decoded = *src++;
+ } else if ((*src & 0xE0) == 0xC0) {
+ min_code = 0x80;
+ decoded = *src++ & 0x1F;
+one_more:
+ if (src == end) {
+ part_decoded_min_code = min_code;
+ part_decoded_char = decoded;
+ part_decoded_rest_len = 1;
+ break;
+ }
+ if ((*src & 0xC0) == 0x80) {
+ decoded = (decoded << 6) | (*src++ & 0x3F);
+ } else {
+ goto invalid_char;
+ }
+ if (decoded < min_code ||
+ decoded > 0x10FFFF ||
+ (0xD800 <= decoded && decoded < 0xE000) || // high/low surrogates
+ (0xFDD0 <= decoded && decoded < 0xFDF0) || // noncharacters
+ (decoded & 0xFFFE) == 0xFFFE) { // noncharacters
+ parse_error("invalid byte sequence in input");
+ }
+ } else if ((*src & 0xF0) == 0xE0) {
+ min_code = 0x800;
+ decoded = *src++ & 0x0F;
+two_more:
+ if (src == end) {
+ part_decoded_min_code = min_code;
+ part_decoded_char = decoded;
+ part_decoded_rest_len = 2;
+ break;
+ }
+ if ((*src & 0xC0) == 0x80) {
+ decoded = (decoded << 6) | (*src++ & 0x3F);
+ } else {
+ goto invalid_char;
+ }
+ goto one_more;
+ } else if ((*src & 0xF8) == 0xF0) {
+ min_code = 0x10000;
+ decoded = *src++ & 0x07;
+three_more:
+ if (src == end) {
+ part_decoded_min_code = min_code;
+ part_decoded_char = decoded;
+ part_decoded_rest_len = 3;
+ break;
+ }
+ if ((*src & 0xC0) == 0x80) {
+ decoded = (decoded << 6) | (*src++ & 0x3F);
+ } else {
+ goto invalid_char;
+ }
+ goto two_more;
+ } else {
+invalid_char:
+ parse_error("invalid byte sequence in input");
+realign:
+ do {
+ ++src;
+ if (src == end) {
+ part_decoded_rest_len = 4;
+ break;
+ }
+ } while ((*src & 0xC0) == 0x80 || (*src & 0xF8) == 0xF8);
+ continue;
+ }
+ *dst++ = decoded;
+ }
+
+ bufpos = buf + MAX_PUTBACK;
+ bufend = dst;
+ } while (bufpos == bufend);
+}
+
+typedef void (*decoder_t)(void);
+
+static decoder_t decoder = decode_utf8;
+
+typedef struct named_decoder_t {
+ char const *name;
+ decoder_t decoder;
+} named_decoder_t;
+
+static named_decoder_t const decoders[] = {
+ { "CP819", decode_iso_8859_1 }, // offical alias
+ { "IBM819", decode_iso_8859_1 }, // offical alias
+ { "ISO-8859-1", decode_iso_8859_1 }, // offical alias
+ { "ISO-8859-15", decode_iso_8859_15 }, // offical name
+ { "ISO8859-1", decode_iso_8859_1 },
+ { "ISO8859-15", decode_iso_8859_15 },
+ { "ISO_8859-1", decode_iso_8859_1 }, // offical alias
+ { "ISO_8859-15", decode_iso_8859_15 }, // offical alias
+ { "ISO_8859-1:1987", decode_iso_8859_1 }, // offical name
+ { "Latin-9", decode_iso_8859_15 }, // offical alias
+ { "UTF-8", decode_utf8 }, // offical name
+ { "csISOLatin1", decode_iso_8859_1 }, // offical alias
+ { "iso-ir-100", decode_iso_8859_1 }, // offical alias
+ { "l1", decode_iso_8859_1 }, // offical alias
+ { "latin1", decode_iso_8859_1 }, // offical alias
+
+ { NULL, NULL }
+};
+
+void select_input_encoding(char const* const encoding)
+{
+ for (named_decoder_t const *i = decoders; i->name != NULL; ++i) {
+ if (strcasecmp(encoding, i->name) != 0)
+ continue;
+ decoder = i->decoder;
+ return;