Mercurial > sdl-ios-xcode
view src/video/Xext/README @ 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 | b87d8d4c205d |
children |
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line source
The reason these libraries are built outside of the standard XFree86 tree is so that they can be linked as shared object code directly into SDL without causing any symbol collisions with code in the application. You can't link static library code into shared libraries on non-x86 Linux platforms. Since these libraries haven't become standard yet, we'll just include them directly. These sources are synchronized with XFree86 4.2.1