annotate 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
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eadc0746dfaf Added SDL_LockRect() and SDL_UnlockRect()
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eadc0746dfaf Added SDL_LockRect() and SDL_UnlockRect()
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2 The reason these libraries are built outside of the standard XFree86
eadc0746dfaf Added SDL_LockRect() and SDL_UnlockRect()
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3 tree is so that they can be linked as shared object code directly into
eadc0746dfaf Added SDL_LockRect() and SDL_UnlockRect()
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4 SDL without causing any symbol collisions with code in the application.
eadc0746dfaf Added SDL_LockRect() and SDL_UnlockRect()
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eadc0746dfaf Added SDL_LockRect() and SDL_UnlockRect()
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6 You can't link static library code into shared libraries on non-x86
eadc0746dfaf Added SDL_LockRect() and SDL_UnlockRect()
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7 Linux platforms. Since these libraries haven't become standard yet,
eadc0746dfaf Added SDL_LockRect() and SDL_UnlockRect()
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8 we'll just include them directly.
eadc0746dfaf Added SDL_LockRect() and SDL_UnlockRect()
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9
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b87d8d4c205d Fixed use of SDL with XInitThreads()
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10 These sources are synchronized with XFree86 4.2.1