From ilya Tue Nov 4 20:51:32 1997 Subject: Re: cperl-mode and emacs-20.2 To: rms@gnu.org Date: Tue, 4 Nov 1997 20:51:32 -0500 (EST) In-Reply-To: <199711041747.KAA10864@chaco.santafe.edu> from "Richard Stallman" at Nov 04, 1997 10:47:04 AM X-Mailer: ELM [version 2.5 PL0b1] Content-Length: 1518 Status: O Richard Stallman writes: > > The patch below is a "cosmetic" workaround. It is "bad" since it > changes semantic of re-match in a restricted buffer, so that what is > after the end of restricted region may affect the match (like removing > word-boundary at the end of restricted region if the region crosses a > word). However, it eliminates the above bug. > > I would rather install a real, correct fix--but I don't really > understand what the problem is. Could you send me a more complete > explanation of how this problem develops? "Correct" is not applicable here, since it is not documented how re-search's lookahead works with restriction. Suppose you have a buffer containing blah and restrict it so it contains "la" instead. Should \> match after "a"? I *think* that the old version would match it, but the patched one would not. Adding to the exlanation in my original message: You asked me to make \s look for syntax-table property. To make this lookup, one needs to know where the properties for the given object are stored (communicated via a global), and offset w.r.t. the start of the object. My code was supposing that the string supplied to re-functions is based at the start of the object. However, it so happens that in a restricted buffer the (char*) is based on the start of restricted region, which breaks the code. Two possible solution might be to communicate offset via another global variable, or somehow deduce it of from the buffer object. Ilya From ilya Wed Oct 29 19:10:03 1997 Subject: Re: cperl-mode and emacs-20.2 To: dsadinof@olf.com (Danny Sadinoff) Date: Wed, 29 Oct 1997 19:10:03 -0500 (EST) Cc: rms@gnu.ai.mit.edu (Richard Stallman) In-Reply-To: <3457A474.2DF3F79C@olf.com> from "Danny Sadinoff" at Oct 29, 1997 04:02:44 PM X-Mailer: ELM [version 2.5 PL0b1] Content-Length: 5794 Status: OR Danny Sadinoff writes: > Okay. on solaris2.5.1, I create a file called 'thefile', whose sole contents are > two lines like so: > #!/usr/bin/perl > hi there > > Then I run emacs like so: > emacs-20.2 -q --no-site-file > > I load cperl-mode manually, then fetch the file. > > When I try to run "M-x comment-region"on the second line of the file I get an error. Almost missed this line... I know this bug. I put a workaround in my copy of 19.33, but did not report it since it was so obvious to find that having no bug reports showed that it should have been fixed in 20.+. Looks like it was not, *and* typical expectation of Emacs user is *very* low. The short description is "making RE-search after restriction fails if parse-sexp-lookup-properties is set". The longer description is re-match-2 takes arguments which are substrings which correspond to the restricted buffer. However, to find the properties, it needs to know where are these substrings wrt to start-of-buffer/string. The patch below is a "cosmetic" workaround. It is "bad" since it changes semantic of re-match in a restricted buffer, so that what is after the end of restricted region may affect the match (like removing word-boundary at the end of restricted region if the region crosses a word). However, it eliminates the above bug. Enjoy, Ilya *** textprop.c~ Fri Mar 14 17:59:24 1997 --- textprop.c Mon Jul 28 00:41:46 1997 *************** interval_of (position, object) *** 539,545 **** i = s->intervals; } ! if (!(beg <= position && position <= end)) args_out_of_range (position, position); if (beg == end || NULL_INTERVAL_P (i)) return NULL_INTERVAL; --- 539,546 ---- i = s->intervals; } ! if (!(beg <= position && position <= end) ! && !(BUFFERP (object) && (position == beg - 1 && beg > 1))) /* lookbehind */ args_out_of_range (position, position); if (beg == end || NULL_INTERVAL_P (i)) return NULL_INTERVAL; *** search.c~ Tue Mar 11 00:15:56 1997 --- search.c Mon Jul 28 00:51:00 1997 *************** looking_at_1 (string, posix) *** 223,249 **** /* Get pointers and sizes of the two strings that make up the visible portion of the buffer. */ ! p1 = BEGV_ADDR; ! s1 = GPT - BEGV; p2 = GAP_END_ADDR; s2 = ZV - GPT; if (s1 < 0) { p2 = p1; ! s2 = ZV - BEGV; s1 = 0; } if (s2 < 0) { ! s1 = ZV - BEGV; s2 = 0; } re_match_object = Qnil; i = re_match_2 (bufp, (char *) p1, s1, (char *) p2, s2, ! PT - BEGV, &search_regs, ! ZV - BEGV); if (i == -2) matcher_overflow (); --- 223,249 ---- /* Get pointers and sizes of the two strings that make up the visible portion of the buffer. */ ! p1 = BEG_ADDR; ! s1 = GPT - 1; p2 = GAP_END_ADDR; s2 = ZV - GPT; if (s1 < 0) { p2 = p1; ! s2 = ZV - 1; s1 = 0; } if (s2 < 0) { ! s1 = ZV - 1; s2 = 0; } re_match_object = Qnil; i = re_match_2 (bufp, (char *) p1, s1, (char *) p2, s2, ! PT - 1, &search_regs, ! ZV - 1); if (i == -2) matcher_overflow (); *************** search_buffer (string, pos, lim, n, RE, *** 808,826 **** /* Get pointers and sizes of the two strings that make up the visible portion of the buffer. */ ! p1 = BEGV_ADDR; ! s1 = GPT - BEGV; p2 = GAP_END_ADDR; s2 = ZV - GPT; if (s1 < 0) { p2 = p1; ! s2 = ZV - BEGV; s1 = 0; } if (s2 < 0) { ! s1 = ZV - BEGV; s2 = 0; } re_match_object = Qnil; --- 808,826 ---- /* Get pointers and sizes of the two strings that make up the visible portion of the buffer. */ ! p1 = BEG_ADDR; ! s1 = GPT - 1; p2 = GAP_END_ADDR; s2 = ZV - GPT; if (s1 < 0) { p2 = p1; ! s2 = ZV - 1; s1 = 0; } if (s2 < 0) { ! s1 = ZV - 1; s2 = 0; } re_match_object = Qnil; *************** search_buffer (string, pos, lim, n, RE, *** 829,844 **** { int val; val = re_search_2 (bufp, (char *) p1, s1, (char *) p2, s2, ! pos - BEGV, lim - pos, &search_regs, /* Don't allow match past current point */ ! pos - BEGV); if (val == -2) { matcher_overflow (); } if (val >= 0) { ! j = BEGV; for (i = 0; i < search_regs.num_regs; i++) if (search_regs.start[i] >= 0) { --- 829,844 ---- { int val; val = re_search_2 (bufp, (char *) p1, s1, (char *) p2, s2, ! pos - 1, lim - pos, &search_regs, /* Don't allow match past current point */ ! pos - 1); if (val == -2) { matcher_overflow (); } if (val >= 0) { ! j = 1; for (i = 0; i < search_regs.num_regs; i++) if (search_regs.start[i] >= 0) { *************** search_buffer (string, pos, lim, n, RE, *** 860,874 **** { int val; val = re_search_2 (bufp, (char *) p1, s1, (char *) p2, s2, ! pos - BEGV, lim - pos, &search_regs, ! lim - BEGV); if (val == -2) { matcher_overflow (); } if (val >= 0) { ! j = BEGV; for (i = 0; i < search_regs.num_regs; i++) if (search_regs.start[i] >= 0) { --- 860,874 ---- { int val; val = re_search_2 (bufp, (char *) p1, s1, (char *) p2, s2, ! pos - 1, lim - pos, &search_regs, ! lim - 1); if (val == -2) { matcher_overflow (); } if (val >= 0) { ! j = 1; for (i = 0; i < search_regs.num_regs; i++) if (search_regs.start[i] >= 0) {