From d0861b4a7cfc6fed74c1450708f5fa0267e8be69 Mon Sep 17 00:00:00 2001
From: "martin f. krafft" <madduck@madduck.net>
Date: Thu, 21 Feb 2019 14:21:43 +1300
Subject: [PATCH] improve format-flowed handling

---
 .vim/after/ftplugin/mail.vim | 87 +++++++++++++++++++++---------------
 1 file changed, 50 insertions(+), 37 deletions(-)

diff --git a/.vim/after/ftplugin/mail.vim b/.vim/after/ftplugin/mail.vim
index 16157a9..245ef06 100644
--- a/.vim/after/ftplugin/mail.vim
+++ b/.vim/after/ftplugin/mail.vim
@@ -1,16 +1,8 @@
 setlocal textwidth=68
 setlocal formatoptions-=o
 setlocal formatoptions-=r
-
-" for format_flowed
-"setlocal formatoptions+=aw
-"setlocal nolist
-"augroup listinsert
-"  autocmd!
-"augroup end
-"augroup tsperrorinsert
-"  autocmd!
-"augroup end
+setlocal formatoptions+=a
+setlocal formatoptions+=w
 
 "setlocal spell
 
@@ -18,16 +10,11 @@ setlocal formatoptions-=r
 " mail, idea from Teemu Likonen:
 " http://groups.google.com/group/vim_use/msg/f59e5c1adc6be2b3
 
-let d_fo = &fo
-let s:defaults = 'setlocal tw=68 ts=2 sts=2 sw=2 fo='.d_fo
+let s:defaults = "setlocal fo=".&fo
+" tw=".&tw." ts=".&ts." sts=".&sts." sw=".&sw." fo=".&fo
 execute s:defaults
 let b:MailAreaDetect=1
 
-"nnoremap <buffer> <LocalLeader>ma1 :call <SID>MailAreaDetect_On()
-"    \ <bar> echo 'MailAreaDetect On'<CR>
-"nnoremap <buffer> <LocalLeader>ma0 :call <SID>MailAreaDetect_Off()
-"    \ <bar> echo 'MailAreaDetect Off'<CR>
-
 nnoremap <buffer><silent> <F9> :call <SID>MailAreaDetect_Switch(0)<CR>
 inoremap <buffer><silent> <F9> <C-\><C-O>:call <SID>MailAreaDetect_Switch(1)<CR>
 
@@ -49,7 +36,6 @@ function! s:MailAreaDetect_Switch(vmode)
     endif
 endfu
 
-
 function! s:MailAreaDetect_On()
     silent autocmd! MailAreaDetect CursorMoved,CursorMoved
         \ <buffer> call <SID>AreaOptions()
@@ -69,21 +55,35 @@ augroup END
 
 function! s:AreaOptions()
     execute s:defaults
-    if <SID>CheckArea('\v^From( |: ).*\n','\v^$')
-        "echo 'Header'
-        setlocal fo-=a fo-=w fo-=t sts=0 sw=2 noet
-    elseif getline('.') =~ '\m^\s*>'
-        "echo 'Quotation'
-        setlocal fo-=a fo-=w
+
+    let s:synCur = synIDattr(synID(line("."),1,0),"name")
+    let s:synNext = synIDattr(synID(line(".")+1,1,0),"name")
+
+    if s:synNext =~ '^mailQuote' && s:synCur == '' && getline('.') =~ '^.'
+      " elseif getline('.') =~ '^\s*[^>]' && getline(line('.')+1) =~ '\m^\s*>'
+      setlocal fo-=a
+      "echo 'Quotation leader (fo='.&fo.')'
+    elseif s:synCur =~ '^mailQuote'
+      " elseif getline('.') =~ '\m^\s*>'
+      setlocal fo-=a
+      "echo 'Quotation (fo='.&fo.')'
     elseif <SID>CheckArea('\m^--- .*\n^+++ ','\v(^$|\n^-- $)')
-        "echo 'Patch'
-        setlocal fo-=a fo-=w fo-=t sts=0 sw=2 noet
-    elseif <SID>CheckArea('^-- $','^$')
-        "echo 'Signature'
-        setlocal fo-=a fo-=w fo-=t sts=0 sw=2 noet
+      setlocal fo-=a fo-=w fo-=t noet
+      "echo 'Patch (fo='.&fo.')'
+    elseif s:synCur == '' && s:synNext =~ '^mailSignature'
+      " elseif getline(line('.')+1) =~ '\m^-- $'
+      setlocal fo-=a fo-=w fo-=t
+      "echo 'Last line before signature (fo='.&fo.')'
+    elseif s:synCur =~ '^mailSignature'
+      " elseif <SID>CheckArea('^-- $','^$')
+      setlocal fo-=a fo-=w fo-=t
+      "echo 'Signature (fo='.&fo.')'
+    elseif s:synCur =~ '^mail'
+      " if <SID>CheckArea('\v^From( |: ).*\n','\v^$')
+      setlocal fo-=a fo-=w fo-=t
+      "echo 'Header (fo='.&fo.')'
     else
-        "echo 'My text'
-        setlocal fo+=aw et
+      "echo 'My text (fo='.&fo.')'
     endif
 endfunction
 
@@ -92,14 +92,27 @@ function! s:CheckArea(start, end)
         \ (search(a:end,'bnW')-line('.'))
 endfunction
 
-augroup tsperrorinsert
-  au!
-augroup END
-match none /\s\+$/
-augroup listinsert
+function! FixQuotes()
+  let l:i = 0
+  let l:lineNxt = getline(l:i)
+  let l:synNxt = synIDattr(synID(l:i,1,0),"name")
+  while l:i < line('$')-1
+    let l:lineCur = l:lineNxt
+    let l:synCur = l:synNxt
+    let l:lineNxt = getline(l:i+1)
+    let l:synNxt = synIDattr(synID(l:i+1,1,0),"name")
+    if l:synCur =~ '^mailQuote' && l:lineCur =~ '\w.*\S$' &&
+          \ l:synNxt =~ '^mailQuote' && l:lineNxt =~ '\w'
+      call setline(l:i, l:lineCur . ' ')
+    endif
+    let l:i += 1
+  endwhile
+endfunction
+
+augroup fixquotes
   au!
+  autocmd BufWinEnter $TMPDIR/mutt-* call FixQuotes()
 augroup END
-set nolist
 
 nmap <buffer> <C-P><F1> :w<CR>:%!mailplate --keep-unknown official<CR>
 nmap <buffer> <C-P><F2> :w<CR>:%!mailplate --keep-unknown tahi<CR>
-- 
2.39.2