* Replaced the UTF8ToCharCode function with one that handles invalid chars

correctly (or at all...)
* Use the common 0xfffd character as a substitute for invalid characters
* Corrected comment

This function is used by the app_server to convert the UTF8 strings to char
codes to feed FreeType. Using a non space substitute character at least for
now, as it makes it more obvious where invalid characters are present.
I tested this change with some UTF8 test files and it seems to work well.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24175 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Michael Lotz
2008-02-28 23:04:47 +00:00
parent 869ca0eb9a
commit 87df690150
+49 -60
View File
@@ -112,81 +112,70 @@ UTF8CountChars(const char *bytes, int32 numBytes)
/*! UTF8ToCharCode converts the input that includes potential multibyte chars
to UTF-32 char codes that can be used by FreeType. The string pointer is
then advanced to the next character in the string. In case the terminating
0 is reached, the string pointer is not advanced anymore and spaces are
0 is reached, the string pointer is not advanced anymore and nulls are
returned. This makes it safe to overruns and enables streamed processing
of UTF8 strings.
*/
static inline uint32
UTF8ToCharCode(const char **bytes)
{
register uint32 result = 0;
#define UTF8_SUBSTITUTE_CHARACTER 0xfffd
if ((*bytes)[0] & 0x80) {
if ((*bytes)[0] & 0x40) {
if ((*bytes)[0] & 0x20) {
if ((*bytes)[0] & 0x10) {
if ((*bytes)[0] & 0x08) {
/* A five byte char?!
Something's wrong, substitute. */
result += 0x20;
(*bytes)++;
return result;
}
if ((*bytes)[1] == 0 || (*bytes)[2] == 0 || (*bytes)[3] == 0)
return 0x00;
/* A four byte char */
result += (*bytes)[0] & 0x07;
result <<= 6;
result += (*bytes)[1] & 0x3f;
result <<= 6;
result += (*bytes)[2] & 0x3f;
result <<= 6;
result += (*bytes)[3] & 0x3f;
(*bytes) += 4;
return result;
}
if ((*bytes)[1] == 0 || (*bytes)[2] == 0)
return 0x00;
/* A three byte char */
result += (*bytes)[0] & 0x0f;
result <<= 6;
result += (*bytes)[1] & 0x3f;
result <<= 6;
result += (*bytes)[2] & 0x3f;
(*bytes) += 3;
return result;
}
if ((*bytes)[1] == 0)
return 0x00;
/* A two byte char */
result += (*bytes)[0] & 0x1f;
result <<= 6;
result += (*bytes)[1] & 0x3f;
(*bytes) += 2;
return result;
uint32 result;
if (((*bytes)[0] & 0x80) == 0) {
// a single byte character
result = (*bytes)[0];
if (result != '\0') {
// do not advance beyond the terminating '\0'
(*bytes)++;
}
/* This (10) is not a startbyte.
Substitute with a space. */
result += 0x20;
(*bytes)++;
return result;
}
if ((*bytes)[0] == 0) {
/* We do not advance beyond the terminating 0. */
if (((*bytes)[0] & 0xc0) == 0x80) {
// not a proper multibyte start
(*bytes)++;
return UTF8_SUBSTITUTE_CHARACTER;
}
// start of a multibyte character
uint8 mask = 0x80;
result = (uint32)((*bytes)[0] & 0xff);
(*bytes)++;
while (result & mask) {
if (mask == 0x02) {
// seven byte char - invalid
return UTF8_SUBSTITUTE_CHARACTER;
}
result &= ~mask;
mask >>= 1;
}
while (((*bytes)[0] & 0xc0) == 0x80) {
result <<= 6;
result += (*bytes)[0] & 0x3f;
(*bytes)++;
mask <<= 1;
if (mask == 0x40)
break;
}
if (mask == 0x40)
return result;
if ((*bytes)[0] == '\0') {
// string terminated within multibyte char
return 0x00;
}
result += (*bytes)[0];
(*bytes)++;
return result;
// not enough bytes in multibyte char
return UTF8_SUBSTITUTE_CHARACTER;
#undef UTF8_SUBSTITUTE_CHARACTER
}
#endif // _UTF8_FUNCTIONS_H