Mercurial > vim
view runtime/indent/mp.vim @ 33815:08f9e1eac4cf v9.0.2123
patch 9.0.2123: Problem with initializing the length of range() lists
Commit: https://github.com/vim/vim/commit/df63da98d8dc284b1c76cfe1b17fa0acbd6094d8
Author: Christian Brabandt <cb@256bit.org>
Date: Thu Nov 23 20:14:28 2023 +0100
patch 9.0.2123: Problem with initializing the length of range() lists
Problem: Problem with initializing the length of range() lists
Solution: Set length explicitly when it shouldn't contain any items
range() may cause a wrong calculation of list length, which may later
then cause a segfault in list_find(). This is usually not a problem,
because range_list_materialize() calculates the length, when it
materializes the list.
In addition, in list_find() when the length of the range was wrongly
initialized, it may seem to be valid, so the check for list index
out-of-bounds will not be true, because it is called before the list is
actually materialized. And so we may eventually try to access a null
pointer, causing a segfault.
So this patch does 3 things:
- In f_range(), when we know that the list should be empty, explicitly
set the list->lv_len value to zero. This should happen, when
start is larger than end (in case the stride is positive) or
end is larger than start when the stride is negative.
This should fix the underlying issue properly. However,
- as a safety measure, let's check that the requested index is not
out of range one more time, after the list has been materialized
and return NULL in case it suddenly is.
- add a few more tests to verify the behaviour.
fixes: #13557
closes: #13563
Co-authored-by: Tim Pope <tpope@github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
author | Christian Brabandt <cb@256bit.org> |
---|---|
date | Thu, 23 Nov 2023 20:30:07 +0100 |
parents | f00c56ee8118 |
children |
line wrap: on
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vim9script # MetaPost indent file # Language: MetaPost # Maintainer: Nicola Vitacolonna <nvitacolonna@gmail.com> # Former Maintainers: Eugene Minkovskii <emin@mccme.ru> # Latest Revision: 2022 Aug 12 if exists("b:did_indent") finish endif b:did_indent = 1 setlocal indentexpr=g:MetaPostIndent() setlocal indentkeys+==end,=else,=fi,=fill,0),0] setlocal nolisp setlocal nosmartindent b:undo_indent = "setl indentexpr< indentkeys< lisp< smartindent<" # Regexps {{{ # Expressions starting indented blocks const MP_OPEN_TAG = [ '\<if\>', '\<else\%[if]\>', '\<for\%(\|ever\|suffixes\)\>', '\<begingroup\>', '\<\%(\|var\|primary\|secondary\|tertiary\)def\>', '^\s*\<begin\%(fig\|graph\|glyph\|char\|logochar\)\>', '[([{]', ]->extend(get(g:, "mp_open_tag", []))->join('\|') # Expressions ending indented blocks const MP_CLOSE_TAG = [ '\<fi\>', '\<else\%[if]\>', '\<end\%(\|for\|group\|def\|fig\|char\|glyph\|graph\)\>', '[)\]}]' ]->extend(get(g:, "mp_close_tag", []))->join('\|') # Statements that may span multiple lines and are ended by a semicolon. To # keep this list short, statements that are unlikely to be very long or are # not very common (e.g., keywords like `interim` or `showtoken`) are not # included. # # The regex for assignments and equations (the last branch) is tricky, because # it must not match things like `for i :=`, `if a=b`, `def...=`, etc... It is # not perfect, but it works reasonably well. const MP_STATEMENT = [ '\<\%(\|un\|cut\)draw\%(dot\)\=\>', '\<\%(\|un\)fill\%[draw]\>', '\<draw\%(dbl\)\=arrow\>', '\<clip\>', '\<addto\>', '\<save\>', '\<setbounds\>', '\<message\>', '\<errmessage\>', '\<errhelp\>', '\<fontmapline\>', '\<pickup\>', '\<show\>', '\<special\>', '\<write\>', '\%(^\|;\)\%([^;=]*\%(' .. MP_OPEN_TAG .. '\)\)\@!.\{-}:\==', ]->join('\|') # A line ends with zero or more spaces, possibly followed by a comment. const EOL = '\s*\%($\|%\)' # }}} # Auxiliary functions {{{ # Returns true if (0-based) position immediately preceding `pos` in `line` is # inside a string or a comment; returns false otherwise. # This is the function that is called more often when indenting, so it is # critical that it is efficient. The method we use is significantly faster # than using syntax attributes, and more general (it does not require # syntax_items). It is also faster than using a single regex matching an even # number of quotes. It helps that MetaPost strings cannot span more than one # line and cannot contain escaped quotes. def IsCommentOrString(line: string, pos: number): bool var in_string = 0 var q = stridx(line, '"') var c = stridx(line, '%') while q >= 0 && q < pos if c >= 0 && c < q if in_string # Find next percent symbol c = stridx(line, '%', q + 1) else # Inside comment return true endif endif in_string = 1 - in_string q = stridx(line, '"', q + 1) # Find next quote endwhile return in_string || (c >= 0 && c <= pos) enddef # Find the first non-comment non-blank line before the given line. def PrevNonBlankNonComment(lnum: number): number var nr = prevnonblank(lnum - 1) while getline(nr) =~# '^\s*%' nr = prevnonblank(nr - 1) endwhile return nr enddef # Returns true if the last tag appearing in the line is an open tag; returns # false otherwise. def LastTagIsOpen(line: string): bool var o = LastValidMatchEnd(line, MP_OPEN_TAG, 0) if o == - 1 return false endif return LastValidMatchEnd(line, MP_CLOSE_TAG, o) < 0 enddef # A simple, efficient and quite effective heuristics is used to test whether # a line should cause the next line to be indented: count the "opening tags" # (if, for, def, ...) in the line, count the "closing tags" (endif, endfor, # ...) in the line, and compute the difference. We call the result the # "weight" of the line. If the weight is positive, then the next line should # most likely be indented. Note that `else` and `elseif` are both opening and # closing tags, so they "cancel out" in almost all cases, the only exception # being a leading `else[if]`, which is counted as an opening tag, but not as # a closing tag (so that, for instance, a line containing a single `else:` # will have weight equal to one, not zero). We do not treat a trailing # `else[if]` in any special way, because lines ending with an open tag are # dealt with separately before this function is called (see MetaPostIndent()). # # Example: # # forsuffixes $=a,b: if x.$ = y.$ : draw else: fill fi # % This line will be indented because |{forsuffixes,if,else}| > |{else,fi}| (3 > 2) # endfor def Weight(line: string): number var o = 0 var i = ValidMatchEnd(line, MP_OPEN_TAG, 0) while i > 0 o += 1 i = ValidMatchEnd(line, MP_OPEN_TAG, i) endwhile var c = 0 i = matchend(line, '^\s*\<else\%[if]\>') # Skip a leading else[if] i = ValidMatchEnd(line, MP_CLOSE_TAG, i) while i > 0 c += 1 i = ValidMatchEnd(line, MP_CLOSE_TAG, i) endwhile return o - c enddef # Similar to matchend(), but skips strings and comments. # line: a String def ValidMatchEnd(line: string, pat: string, start: number): number var i = matchend(line, pat, start) while i > 0 && IsCommentOrString(line, i) i = matchend(line, pat, i) endwhile return i enddef # Like s:ValidMatchEnd(), but returns the end position of the last (i.e., # rightmost) match. def LastValidMatchEnd(line: string, pat: string, start: number): number var last_found = -1 var i = matchend(line, pat, start) while i > 0 if !IsCommentOrString(line, i) last_found = i endif i = matchend(line, pat, i) endwhile return last_found enddef def DecreaseIndentOnClosingTag(curr_indent: number): number var cur_text = getline(v:lnum) if cur_text =~# '^\s*\%(' .. MP_CLOSE_TAG .. '\)' return max([curr_indent - shiftwidth(), 0]) endif return curr_indent enddef # }}} # Main function {{{ def g:MetaPostIndent(): number # Do not touch indentation inside verbatimtex/btex.. etex blocks. if synIDattr(synID(v:lnum, 1, 1), "name") =~# '^mpTeXinsert$\|^tex\|^Delimiter' return -1 endif # At the start of a MetaPost block inside ConTeXt, do not touch indentation if synIDattr(synID(prevnonblank(v:lnum - 1), 1, 1), "name") == "contextBlockDelim" return -1 endif var lnum = PrevNonBlankNonComment(v:lnum) # At the start of the file use zero indent. if lnum == 0 return 0 endif var prev_text = getline(lnum) # Every rule of indentation in MetaPost is very subjective. We might get # creative, but things get murky very soon (there are too many corner # cases). So, we provide a means for the user to decide what to do when this # script doesn't get it. We use a simple idea: use '%>', '%<', '%=', and # '%!', to explicitly control indentation. The '<' and '>' symbols may be # repeated many times (e.g., '%>>' will cause the next line to be indented # twice). # # User-defined overrides take precedence over anything else. var j = match(prev_text, '%[<>=!]') if j > 0 var i = strlen(matchstr(prev_text, '%>\+', j)) - 1 if i > 0 return indent(lnum) + i * shiftwidth() endif i = strlen(matchstr(prev_text, '%<\+', j)) - 1 if i > 0 return max([indent(lnum) - i * shiftwidth(), 0]) endif if match(prev_text, '%=', j) > -1 return indent(lnum) endif if match(prev_text, '%!', j) > -1 return -1 endif endif # If the reference line ends with an open tag, indent. # # Example: # # if c: # 0 # else: # 1 # fi if c2: % Note that this line has weight equal to zero. # ... % This line will be indented if LastTagIsOpen(prev_text) return DecreaseIndentOnClosingTag(indent(lnum) + shiftwidth()) endif # Lines with a positive weight are unbalanced and should likely be indented. # # Example: # # def f = enddef for i = 1 upto 5: if x[i] > 0: 1 else: 2 fi # ... % This line will be indented (because of the unterminated `for`) if Weight(prev_text) > 0 return DecreaseIndentOnClosingTag(indent(lnum) + shiftwidth()) endif # Unterminated statements cause indentation to kick in. # # Example: # # draw unitsquare # withcolor black; % This line is indented because of `draw`. # x := a + b + c # + d + e; % This line is indented because of `:=`. # var i = LastValidMatchEnd(prev_text, MP_STATEMENT, 0) if i >= 0 # Does the line contain a statement? if ValidMatchEnd(prev_text, ';', i) < 0 # Is the statement unterminated? return indent(lnum) + shiftwidth() else return DecreaseIndentOnClosingTag(indent(lnum)) endif endif # Deal with the special case of a statement spanning multiple lines. If the # current reference line L ends with a semicolon, search backwards for # another semicolon or a statement keyword. If the latter is found first, # its line is used as the reference line for indenting the current line # instead of L. # # Example: # # if cond: # draw if a: z0 else: z1 fi # shifted S # scaled T; % L # # for i = 1 upto 3: % <-- Current line: this gets the same indent as `draw ...` # # NOTE: we get here only if L does not contain a statement (among those # listed in g:MP_STATEMENT). if ValidMatchEnd(prev_text, ';' .. EOL, 0) >= 0 # L ends with a semicolon var stm_lnum = PrevNonBlankNonComment(lnum) while stm_lnum > 0 prev_text = getline(stm_lnum) var sc_pos = LastValidMatchEnd(prev_text, ';', 0) var stm_pos = ValidMatchEnd(prev_text, MP_STATEMENT, sc_pos) if stm_pos > sc_pos lnum = stm_lnum break elseif sc_pos > stm_pos break endif stm_lnum = PrevNonBlankNonComment(stm_lnum) endwhile endif return DecreaseIndentOnClosingTag(indent(lnum)) enddef # }}} # vim: sw=2 fdm=marker