Mercurial > sdl-ios-xcode
comparison src/stdlib/SDL_iconv.c @ 3539:f2846bf19360
Fixed bug #896
John Popplewell 2009-12-08 23:05:50 PST
Originally reported by AKFoerster on the mailing list.
Error decoding UTF8 Russian text to UTF-16LE on Windows, but specifically on
platforms without iconv support (the default on Windows).
Valid UTF8 characters are flagged as being overlong and then substituted by the
UNKNOWN_UNICODE character.
After studying the testiconv.c example program, reading the RFCs and putting
some printf statements in SDL_iconv.c the problem is in a test for 'Maximum
overlong sequences', specifically 4.2.1, which is carried out by the following
code:
} else if ( p[0] >= 0xC0 ) {
if ( (p[0] & 0xE0) != 0xC0 ) {
/* Skip illegal sequences
return SDL_ICONV_EILSEQ;
*/
ch = UNKNOWN_UNICODE;
} else {
if ( (p[0] & 0xCE) == 0xC0 ) { <<<<<<<< here
overlong = SDL_TRUE;
}
ch = (Uint32)(p[0] & 0x1F);
left = 1;
}
} else {
Here is the 2-byte encoding of a character in range 00000080 - 000007FF
110xxxxx 10xxxxxx
The line in question is supposed to be checking for an overlong sequence which
would be less than
11000001 10111111
which should be represented as a single byte.
BUT, the mask value (0xCE) is wrong, it isn't checking the top-most bit:
11000001 value
11001110 mask (incorrect)
^
and should be (0xDE):
11000001 value
11011110 mask (correct)
making the above code:
} else if ( p[0] >= 0xC0 ) {
if ( (p[0] & 0xE0) != 0xC0 ) {
/* Skip illegal sequences
return SDL_ICONV_EILSEQ;
*/
ch = UNKNOWN_UNICODE;
} else {
if ( (p[0] & 0xDE) == 0xC0 ) { <<<<<<<< here
overlong = SDL_TRUE;
}
ch = (Uint32)(p[0] & 0x1F);
left = 1;
}
} else {
I can supply a test program and/or a patch if required,
best regards,
John Popplewell
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Fri, 11 Dec 2009 08:03:43 +0000 |
parents | b225c8a7896e |
children | f7b03b6838cb |
comparison
equal
deleted
inserted
replaced
3538:a1896642a47e | 3539:f2846bf19360 |
---|---|
389 /* Skip illegal sequences | 389 /* Skip illegal sequences |
390 return SDL_ICONV_EILSEQ; | 390 return SDL_ICONV_EILSEQ; |
391 */ | 391 */ |
392 ch = UNKNOWN_UNICODE; | 392 ch = UNKNOWN_UNICODE; |
393 } else { | 393 } else { |
394 if ((p[0] & 0xCE) == 0xC0) { | 394 if ((p[0] & 0xDE) == 0xC0) { |
395 overlong = SDL_TRUE; | 395 overlong = SDL_TRUE; |
396 } | 396 } |
397 ch = (Uint32) (p[0] & 0x1F); | 397 ch = (Uint32) (p[0] & 0x1F); |
398 left = 1; | 398 left = 1; |
399 } | 399 } |