SDL-devel-1.2.13-mingw32.tar.gz

UTF-8 decoder capability and stress test ---------------------------------------- Markus Kuhn <http://www.cl.cam.ac.uk/~mgk25/> - 2003-02-19 This test file can help you examine, how your UTF-8 decoder handles various types of correct, malformed, or otherwise interesting UTF-8 sequences. This file is not meant to be a conformance test. It does not prescribes any particular outcome and therefore there is no way to "pass" or "fail" this test file, even though the texts suggests a preferable decoder behaviour at some places. The aim is instead to help you think about and test the behaviour of your UTF-8 on a systematic collection of unusual inputs. Experience so far suggests that most first-time authors of UTF-8 decoders find at least one serious problem in their decoder by using this file. The test lines below cover boundary conditions, malformed UTF-8 sequences as well as correctly encoded UTF-8 sequences of Unicode code points that should never occur in a correct UTF-8 file. According to ISO 10646-1:2000, sections D.7 and 2.3c, a device receiving UTF-8 shall interpret a "malformed sequence in the same way that it interprets a character that is outside the adopted subset" and "characters that are not within the adopted subset shall be indicated to the user" by a receiving device. A quite commonly used approach in UTF-8 decoders is to replace any malformed UTF-8 sequence by a replacement character (U+FFFD), which looks a bit like an inverted question mark, or a similar symbol. It might be a good idea to visually distinguish a malformed UTF-8 sequence from a correctly encoded Unicode character that is just not available in the current font but otherwise fully legal, even though ISO 10646-1 doesn't mandate this. In any case, just ignoring malformed sequences or unavailable characters does not conform to ISO 10646, will make debugging more difficult, and can lead to user confusion. Please check, whether a malformed UTF-8 sequence is (1) represented at all, (2) represented by exactly one single replacement character (or equivalent signal), and (3) the following quotation mark after an illegal UTF-8 sequence is correctly displayed, i.e. proper resynchronization takes place immageately after any malformed sequence. This file says "THE END" in the last line, so if you don't see that, your decoder crashed somehow before, which should always be cause for concern. All lines in this file are exactly 79 characters long (plus the line feed). In addition, all lines end with "|", except for the two test lines 2.1.1 and 2.2.1, which contain non-printable ASCII controls U+0000 and U+007F. If you display this file with a fixed-width font, these "|" characters should all line up in column 79 (right margin). This allows you to test quickly, whether your UTF-8 decoder finds the correct number of characters in every line, that is whether each malformed sequences is replaced by a single replacement character. Note that as an alternative to the notion of malformed sequence used here, it is also a perfectly acceptable (and in some situations even preferable) solution to represent each individual byte of a malformed sequence by a replacement character. If you follow this strategy in your decoder, then please ignore the "|" column. Here come the tests: | | 1 Some correct UTF-8 text | | (The codepoints for this test are: | U+03BA U+1F79 U+03C3 U+03BC U+03B5 --ryan.) | | You should see the Greek word 'kosme': "κόσμε" | | | 2 Boundary condition test cases | | 2.1 First possible sequence of a certain length | | (byte zero skipped...there's a null added at the end of the test. --ryan.) | | 2.1.2 2 bytes (U-00000080): "€" | 2.1.3 3 bytes (U-00000800): "ࠀ" | 2.1.4 4 bytes (U-00010000): "𐀀" | | (5 and 6 byte sequences were made illegal in rfc3629. --ryan.) | 2.1.5 5 bytes (U-00200000): "øˆ€€€" | 2.1.6 6 bytes (U-04000000): "ü„€€€€" | | 2.2 Last possible sequence of a certain length | | 2.2.1 1 byte (U-0000007F): "" | 2.2.2 2 bytes (U-000007FF): "ß¿" | | (Section 5.3.2 below calls this illegal. --ryan.) | 2.2.3 3 bytes (U-0000FFFF): "ï¿¿" | | (5 and 6 bytes sequences, and 4 bytes sequences > 0x10FFFF were made illegal | in rfc3629, so these next three should be replaced with a invalid | character codepoint. --ryan.) | 2.2.4 4 bytes (U-001FFFFF): "÷¿¿¿" | 2.2.5 5 bytes (U-03FFFFFF): "û¿¿¿¿" | 2.2.6 6 bytes (U-7FFFFFFF): "ý¿¿¿¿¿" | | 2.3 Other boundary conditions | | 2.3.1 U-0000D7FF = ed 9f bf = "퟿" | 2.3.2 U-0000E000 = ee 80 80 = "" | 2.3.3 U-0000FFFD = ef bf bd = "�" | 2.3.4 U-0010FFFF = f4 8f bf bf = "ô¿¿" | | (This one is bogus in rfc3629. --ryan.) | 2.3.5 U-00110000 = f4 90 80 80 = "ô€€" | | 3 Malformed sequences | | 3.1 Unexpected continuation bytes | | Each unexpected continuation byte should be separately signalled as a | malformed sequence of its own. | | 3.1.1 First continuation byte 0x80: "€" | 3.1.2 Last continuation byte 0xbf: "¿" |