patch 9.1.0645: regex: wrong match when searching multi-byte char case-insensitive
Commit: https://github.com/vim/vim/commit/22e8e12d9f5034e1984db0c567b281fda4de8dd7 Author: Christian Brabandt <c...@256bit.org> Date: Tue Jul 30 20:39:18 2024 +0200 patch 9.1.0645: regex: wrong match when searching multi-byte char case-insensitive Problem: regex: wrong match when searching multi-byte char case-insensitive (diffsetter) Solution: Apply proper case-folding for characters and search-string This patch does the following 4 things: 1) When the regexp engine compares two utf-8 codepoints case insensitive it may match an adjacent character, because it assumes it can step over as many bytes as the pattern contains. This however is not necessarily true because of case-folding, a multi-byte UTF-8 character can be considered equal to some single-byte value. Let's consider the pattern 'ſ' and the string 's'. When comparing and ignoring case, the single character 's' matches, and since it matches Vim will try to step over the match (by the amount of bytes of the pattern), assuming that since it matches, the length of both strings is the same. However in that case, it should only step over the single byte value 's' by 1 byte and try to start matching after it again. So for the backtracking engine we need to ensure: * we try to match the correct length for the pattern and the text * in case of a match, we step over it correctly There is one tricky thing for the backtracing engine. We also need to calculate correctly the number of bytes to compare the 2 different utf-8 strings s1 and s2. So we will count the number of characters in s1 that the byte len specified. Then we count the number of bytes to step over the same number of characters in string s2 and then we can correctly compare the 2 utf-8 strings. 2) A similar thing can happen for the NFA engine, when skipping to the next character to test for a match. We are skipping over the regstart pointer, however we do not consider the case that because of case-folding we may need to adjust the number of bytes to skip over. So this needs to be adjusted in find_match_text() as well. 3) A related issue turned out, when prog->match_text is actually empty. In that case we should try to find the next match and skip this condition. 4) When comparing characters using collections, we must also apply case folding to each character in the collection and not just to the current character from the search string. This doesn't apply to the NFA engine, because internally it converts collections to branches [abc] -> a\|b\|c fixes: #14294 closes: #14756 Signed-off-by: Christian Brabandt <c...@256bit.org> diff --git a/runtime/doc/version9.txt b/runtime/doc/version9.txt index e8e9194dc..73e54a1cf 100644 --- a/runtime/doc/version9.txt +++ b/runtime/doc/version9.txt @@ -1,4 +1,4 @@ -*version9.txt* For Vim version 9.1. Last change: 2024 Jul 28 +*version9.txt* For Vim version 9.1. Last change: 2024 Jul 30 VIM REFERENCE MANUAL by Bram Moolenaar @@ -41590,6 +41590,8 @@ Changed~ behaviour/inconsistency (see |d-special| and |cw|). - allow to specify additional attributes in the completion menu (allows to mark deprecated attributes from LSP server) |complete-items| +- the regex engines match correctly case-insensitive multi-byte characters + (and apply proper case folding) *added-9.2* Added ~ diff --git a/src/mbyte.c b/src/mbyte.c index a68ba7be3..d8c47acdd 100644 --- a/src/mbyte.c +++ b/src/mbyte.c @@ -3800,6 +3800,15 @@ utf_strnicmp( * Returns zero if s1 and s2 are equal (ignoring case), the difference between * two characters otherwise. */ + int +mb_strnicmp2(char_u *s1, char_u *s2, size_t n1, size_t n2) +{ + if (n1 == n2 || !enc_utf8) + return mb_strnicmp(s1, s2, n1); + else + return utf_strnicmp(s1, s2, n1, n2); +} + int mb_strnicmp(char_u *s1, char_u *s2, size_t nn) { diff --git a/src/proto/mbyte.pro b/src/proto/mbyte.pro index c57c94c8a..bb976e3bf 100644 --- a/src/proto/mbyte.pro +++ b/src/proto/mbyte.pro @@ -48,6 +48,7 @@ int utf_islower(int a); int utf_tolower(int a); int utf_isupper(int a); int mb_strnicmp(char_u *s1, char_u *s2, size_t nn); +int mb_strnicmp2(char_u *s1, char_u *s2, size_t n1, size_t n2); void show_utf8(void); int latin_head_off(char_u *base, char_u *p); int dbcs_screen_head_off(char_u *base, char_u *p); diff --git a/src/regexp.c b/src/regexp.c index ff201d9ff..a1b080e7d 100644 --- a/src/regexp.c +++ b/src/regexp.c @@ -1729,7 +1729,9 @@ mb_decompose(int c, int *c1, int *c2, int *c3) /* * Compare two strings, ignore case if rex.reg_ic set. * Return 0 if strings match, non-zero otherwise. - * Correct the length "*n" when composing characters are ignored. + * Correct the length "*n" when composing characters are ignored + * or for utf8 when both utf codepoints are considered equal because of + * case-folding but have different length (e.g. 's' and 'ſ') */ static int cstrncmp(char_u *s1, char_u *s2, int *n) @@ -1738,6 +1740,29 @@ cstrncmp(char_u *s1, char_u *s2, int *n) if (!rex.reg_ic) result = STRNCMP(s1, s2, *n); + else if (enc_utf8) + { + char_u *p = s1; + size_t n2 = 0; + int n1 = *n; + // count the number of characters for byte-length of s1 + while (n1 > 0 && *p != NUL) + { + n1 -= mb_ptr2len(s1); + MB_PTR_ADV(p); + n2++; + } + // count the number of bytes to advance the same number of chars for s2 + p = s2; + while (n2-- > 0 && *p != NUL) + MB_PTR_ADV(p); + + n2 = p - s2; + + result = MB_STRNICMP2(s1, s2, *n, n2); + if (result == 0 && (int)n2 < *n) + *n = n2; + } else result = MB_STRNICMP(s1, s2, *n); @@ -1787,7 +1812,7 @@ cstrncmp(char_u *s1, char_u *s2, int *n) cstrchr(char_u *s, int c) { char_u *p; - int cc; + int cc, lc; if (!rex.reg_ic || (!enc_utf8 && mb_char2len(c) > 1)) return vim_strchr(s, c); @@ -1796,26 +1821,35 @@ cstrchr(char_u *s, int c) // faster (esp. when using MS Visual C++!). // For UTF-8 need to use folded case. if (enc_utf8 && c > 0x80) + { cc = utf_fold(c); + lc = cc; + } else - if (MB_ISUPPER(c)) - cc = MB_TOLOWER(c); - else if (MB_ISLOWER(c)) - cc = MB_TOUPPER(c); - else - return vim_strchr(s, c); + if (MB_ISUPPER(c)) + { + cc = MB_TOLOWER(c); + lc = cc; + } + else if (MB_ISLOWER(c)) + { + cc = MB_TOUPPER(c); + lc = c; + } + else + return vim_strchr(s, c); if (has_mbyte) { for (p = s; *p != NUL; p += (*mb_ptr2len)(p)) { - if (enc_utf8 && c > 0x80) + int uc = utf_ptr2char(p); + if (enc_utf8 && (c > 0x80 || uc > 0x80)) { - int uc = utf_ptr2char(p); - // Do not match an illegal byte. E.g. 0xff matches 0xc3 0xbf, // not 0xff. - if ((uc < 0x80 || uc != *p) && utf_fold(uc) == cc) + // compare with lower case of the character + if ((uc < 0x80 || uc != *p) && utf_fold(uc) == lc) return p; } else if (*p == c || *p == cc) diff --git a/src/regexp_bt.c b/src/regexp_bt.c index 5452dda0f..16dac730d 100644 --- a/src/regexp_bt.c +++ b/src/regexp_bt.c @@ -3823,6 +3823,14 @@ regmatch( } } } + else if (enc_utf8) + { + if (cstrncmp(opnd, rex.input, &len) != 0) + { + status = RA_NOMATCH; + break; + } + } else for (i = 0; i < len; ++i) if (opnd[i] != rex.input[i]) diff --git a/src/regexp_nfa.c b/src/regexp_nfa.c index 4f07a21d5..6db413462 100644 --- a/src/regexp_nfa.c +++ b/src/regexp_nfa.c @@ -5666,7 +5666,12 @@ find_match_text(colnr_T *startcol, int regstart, char_u *match_text) for (;;) { match = TRUE; - len2 = MB_CHAR2LEN(regstart); // skip regstart + // skip regstart + len2 = MB_CHAR2LEN(regstart); + if (enc_utf8 && len2 > 1 && MB_CHAR2LEN(PTR2CHAR(rex.line + col)) != len2) + // because of case-folding of the previously matched text, we may need + // to skip fewer bytes than mb_char2len(regstart) + len2 = mb_char2len(utf_fold(regstart)); for (len1 = 0; match_text[len1] != NUL; len1 += MB_CHAR2LEN(c1)) { c1 = PTR2CHAR(match_text + len1); @@ -7502,7 +7507,7 @@ nfa_regexec_both( // If match_text is set it contains the full text that must match. // Nothing else to try. Doesn't handle combining chars well. - if (prog->match_text != NULL && !rex.reg_icombine) + if (prog->match_text != NULL && *prog->match_text != NUL && !rex.reg_icombine) { retval = find_match_text(&col, prog->regstart, prog->match_text); if (REG_MULTI) diff --git a/src/testdir/test_regexp_utf8.vim b/src/testdir/test_regexp_utf8.vim index bc705441e..51c0984ad 100644 --- a/src/testdir/test_regexp_utf8.vim +++ b/src/testdir/test_regexp_utf8.vim @@ -587,4 +587,36 @@ func Test_combining_chars_in_collection() bw! endfunc +func Test_search_multibyte_match_ascii() + new + " Match single 'ſ' and 's' + call setline(1, 'das abc heraus abc ſich abc ſind') + for i in range(0, 2) + exe "set re="..i + let ic_match = matchbufline('%', ' -- -- You received this message from the "vim_dev" maillist. Do not top-post! Type your reply below the text you are replying to. For more information, visit http://www.vim.org/maillist.php --- You received this message because you are subscribed to the Google Groups "vim_dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to vim_dev+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/vim_dev/E1sYrqK-0043F0-5Q%40256bit.org.
