add securemodelines.vim

Signed-off-by: Colin McCabe <cmccabe@alumni.cmu.edu>

diff --git a/.vim/plugin/securemodelines.vim b/.vim/plugin/securemodelines.vim
new file mode 100644 (file)
index 0000000..58c3e51
--- /dev/null
+++ b/.vim/plugin/securemodelines.vim
@@ -0,0 +1,152 @@
+" vim: set sw=4 sts=4 et ft=vim :
+" Script:           securemodelines.vim
+" Author:           Ciaran McCreesh <ciaran.mccreesh at googlemail.com>
+" Homepage:         http://github.com/ciaranm/securemodelines
+" Requires:         Vim 7
+" License:          Redistribute under the same terms as Vim itself
+" Purpose:          A secure alternative to modelines
+
+if &compatible || v:version < 700 || exists('g:loaded_securemodelines')
+    finish
+endif
+let g:loaded_securemodelines = 1
+
+if (! exists("g:secure_modelines_allowed_items"))
+    let g:secure_modelines_allowed_items = [
+                \ "textwidth",   "tw",
+                \ "softtabstop", "sts",
+                \ "tabstop",     "ts",
+                \ "shiftwidth",  "sw",
+                \ "expandtab",   "et",   "noexpandtab", "noet",
+                \ "filetype",    "ft",
+                \ "foldmethod",  "fdm",
+                \ "readonly",    "ro",   "noreadonly", "noro",
+                \ "rightleft",   "rl",   "norightleft", "norl",
+                \ "cindent",     "cin",  "nocindent", "nocin",
+                \ "smartindent", "si",   "nosmartindent", "nosi",
+                \ "autoindent",  "ai",   "noautoindent", "noai",
+                \ "spell",
+                \ "spelllang"
+                \ ]
+endif
+
+if (! exists("g:secure_modelines_verbose"))
+    let g:secure_modelines_verbose = 0
+endif
+
+if (! exists("g:secure_modelines_modelines"))
+    let g:secure_modelines_modelines=5
+endif
+
+if (! exists("g:secure_modelines_leave_modeline"))
+    if &modeline
+        set nomodeline
+        if g:secure_modelines_verbose
+            echohl WarningMsg
+            echo "Forcibly disabling internal modelines for securemodelines.vim"
+            echohl None
+        endif
+    endif
+endif
+
+fun! <SID>IsInList(list, i) abort
+    for l:item in a:list
+        if a:i == l:item
+            return 1
+        endif
+    endfor
+    return 0
+endfun
+
+fun! <SID>DoOne(item) abort
+    let l:matches = matchlist(a:item, '^\([a-z]\+\)\%([-+^]\?=[a-zA-Z0-9_\-.]\+\)\?$')
+    if len(l:matches) > 0
+        if <SID>IsInList(g:secure_modelines_allowed_items, l:matches[1])
+            exec "setlocal " . a:item
+        elseif g:secure_modelines_verbose
+            echohl WarningMsg
+            echo "Ignoring '" . a:item . "' in modeline"
+            echohl None
+        endif
+    endif
+endfun
+
+fun! <SID>DoNoSetModeline(line) abort
+    for l:item in split(a:line, '[ \t:]')
+        call <SID>DoOne(l:item)
+    endfor
+endfun
+
+fun! <SID>DoSetModeline(line) abort
+    for l:item in split(a:line)
+        call <SID>DoOne(l:item)
+    endfor
+endfun
+
+fun! <SID>CheckVersion(op, ver) abort
+    if a:op == "="
+        return v:version != a:ver
+    elseif a:op == "<"
+        return v:version < a:ver
+    elseif a:op == ">"
+        return v:version >= a:ver
+    else
+        return 0
+    endif
+endfun
+
+fun! <SID>DoModeline(line) abort
+    let l:matches = matchlist(a:line, '\%(\S\@<!\%(vi\|vim\([<>=]\?\)\([0-9]\+\)\?\)\|\sex\):\s*\%(set\s\+\)\?\([^:]\+\):\S\@!')
+    if len(l:matches) > 0
+        let l:operator = ">"
+        if len(l:matches[1]) > 0
+            let l:operator = l:matches[1]
+        endif
+        if len(l:matches[2]) > 0
+            if <SID>CheckVersion(l:operator, l:matches[2]) ? 0 : 1
+                return
+            endif
+        endif
+        return <SID>DoSetModeline(l:matches[3])
+    endif
+
+    let l:matches = matchlist(a:line, '\%(\S\@<!\%(vi\|vim\([<>=]\?\)\([0-9]\+\)\?\)\|\sex\):\(.\+\)')
+    if len(l:matches) > 0
+        let l:operator = ">"
+        if len(l:matches[1]) > 0
+            let l:operator = l:matches[1]
+        endif
+        if len(l:matches[2]) > 0
+            if <SID>CheckVersion(l:operator, l:matches[2]) ? 0 : 1
+                return
+            endif
+        endif
+        return <SID>DoNoSetModeline(l:matches[3])
+    endif
+endfun
+
+fun! <SID>DoModelines() abort
+    if line("$") > g:secure_modelines_modelines
+        let l:lines={ }
+        call map(filter(getline(1, g:secure_modelines_modelines) +
+                    \ getline(line("$") - g:secure_modelines_modelines, "$"),
+                    \ 'v:val =~ ":"'), 'extend(l:lines, { v:val : 0 } )')
+        for l:line in keys(l:lines)
+            call <SID>DoModeline(l:line)
+        endfor
+    else
+        for l:line in getline(1, "$")
+            call <SID>DoModeline(l:line)
+        endfor
+    endif
+endfun
+
+fun! SecureModelines_DoModelines() abort
+    call <SID>DoModelines()
+endfun
+
+aug SecureModeLines
+    au!
+    au BufRead,StdinReadPost * :call <SID>DoModelines()
+aug END
+