diff options
Diffstat (limited to 'utf8.c')
| -rw-r--r-- | utf8.c | 23 |
1 files changed, 15 insertions, 8 deletions
@@ -1278,19 +1278,26 @@ Perl_utf16_to_utf8(pTHX_ U8* p, U8* d, I32 bytelen, I32 *newlen) #define LAST_HIGH_SURROGATE 0xDBFF #define FIRST_LOW_SURROGATE 0xDC00 #define LAST_LOW_SURROGATE UNICODE_SURROGATE_LAST - if (uv >= FIRST_HIGH_SURROGATE && uv <= LAST_HIGH_SURROGATE) { - if (p >= pend) { - Perl_croak(aTHX_ "Malformed UTF-16 surrogate"); - } else { + + /* This assumes that most uses will be in the first Unicode plane, not + * needing surrogates */ + if (UNLIKELY(uv >= UNICODE_SURROGATE_FIRST + && uv <= UNICODE_SURROGATE_LAST)) + { + if (UNLIKELY(p >= pend) || UNLIKELY(uv > LAST_HIGH_SURROGATE)) { + Perl_croak(aTHX_ "Malformed UTF-16 surrogate"); + } + else { UV low = (p[0] << 8) + p[1]; - p += 2; - if (low < FIRST_LOW_SURROGATE || low > LAST_LOW_SURROGATE) + if ( UNLIKELY(low < FIRST_LOW_SURROGATE) + || UNLIKELY(low > LAST_LOW_SURROGATE)) + { Perl_croak(aTHX_ "Malformed UTF-16 surrogate"); + } + p += 2; uv = ((uv - FIRST_HIGH_SURROGATE) << 10) + (low - FIRST_LOW_SURROGATE) + 0x10000; } - } else if (uv >= FIRST_LOW_SURROGATE && uv <= LAST_LOW_SURROGATE) { - Perl_croak(aTHX_ "Malformed UTF-16 surrogate"); } #ifdef EBCDIC d = uvoffuni_to_utf8_flags(d, uv, 0); |