With FEATURE_VI_REGEX_SEARCH enabled backward searches don't work. This is problematic on distros that enable regexes, such as Tiny Core Linux and Fedora.
When calling GNU re_search() with a negative range parameter (indicating a backward search) the start offset must be set to the end of the area being searched. The return value of re_search() is the offset of the matched pattern from the start of the area being searched. For a successful search (positive return value) char_search() can return the pointer to the start of the area plus the offset. FEATURE_VI_REGEX_SEARCH isn't enabled by default but when it is: function old new delta char_search 256 247 -9 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-9) Total: -9 bytes Signed-off-by: Andrey Dobrovolsky <[email protected]> Signed-off-by: Ron Yorston <[email protected]> --- editors/vi.c | 33 +++++++++++++-------------------- 1 file changed, 13 insertions(+), 20 deletions(-) diff --git a/editors/vi.c b/editors/vi.c index d85cdd98d..87d6a628e 100644 --- a/editors/vi.c +++ b/editors/vi.c @@ -2371,9 +2371,7 @@ static char *char_search(char *p, const char *pat, int dir_and_range) struct re_pattern_buffer preg; const char *err; char *q; - int i; - int size; - int range; + int i, size, range, start; re_syntax_options = RE_SYNTAX_POSIX_EXTENDED; if (ignorecase) @@ -2398,31 +2396,26 @@ static char *char_search(char *p, const char *pat, int dir_and_range) // RANGE could be negative if we are searching backwards range = q - p; - q = p; - size = range; if (range < 0) { - size = -size; - q = p - size; - if (q < text) - q = text; + size = -range; + start = size; + } else { + size = range; + start = 0; } + q = p - start; + if (q < text) + q = text; // search for the compiled pattern, preg, in p[] - // range < 0: search backward - // range > 0: search forward - // 0 < start < size + // range < 0, start == size: search backward + // range > 0, start == 0: search forward // re_search() < 0: not found or error // re_search() >= 0: index of found pattern // struct pattern char int int int struct reg // re_search(*pattern_buffer, *string, size, start, range, *regs) - i = re_search(&preg, q, size, /*start:*/ 0, range, /*struct re_registers*:*/ NULL); + i = re_search(&preg, q, size, start, range, /*struct re_registers*:*/ NULL); regfree(&preg); - if (i < 0) - return NULL; - if (dir_and_range > 0) // FORWARD? - p = p + i; - else - p = p - i; - return p; + return i < 0 ? NULL : q + i; } # else # if ENABLE_FEATURE_VI_SETOPTS -- 2.31.1 _______________________________________________ busybox mailing list [email protected] http://lists.busybox.net/mailman/listinfo/busybox
