From c4773a9b8e0ac823009bb342b2642f780de33cdc Mon Sep 17 00:00:00 2001
From: Alexandre Constantino <dreaming.about.electric.sheep@gmail.com>
Date: Tue, 12 Jan 2016 17:37:16 +0000
Subject: [PATCH 1/1] Fix bug related to folding and hash comments

Fix bug that occurs when hash comments are used in fenced code blocks.
Fix same problem that occurs when building a TOC with the :Toc command.
Add flag that allow the user to set folding level, by default set to 1.
---
 README.md                   | 16 ++++++++++++++++
 after/ftplugin/markdown.vim | 38 ++++++++++++++++++++++++++++++-------
 ftplugin/markdown.vim       | 28 +++++++++++++++++++++++----
 3 files changed, 71 insertions(+), 11 deletions(-)

diff --git a/README.md b/README.md
index d2ed419..da77a07 100644
--- a/README.md
+++ b/README.md
@@ -109,6 +109,22 @@ Highlight YAML frontmatter as used by Jekyll:
 let g:vim_markdown_frontmatter=1
 ```
 
+#### Folding level
+
+Folding level is a number between 1 and 6. By default, if not specified, it is set to 1.
+
+```vim
+let g:vim_markdown_folding_level = 6
+```
+
+Tip: it can be changed on the fly with:
+
+```vim
+:let g:vim_markdown_folding_level = 1
+:edit
+```
+
+
 ## Mappings
 
 The following work on normal and visual modes:
diff --git a/after/ftplugin/markdown.vim b/after/ftplugin/markdown.vim
index d965a71..f6bfe47 100644
--- a/after/ftplugin/markdown.vim
+++ b/after/ftplugin/markdown.vim
@@ -47,6 +47,20 @@ if get(g:, "vim_markdown_folding_style_pythonic", 0)
     endfunction
 else
     function! Foldexpr_markdown(lnum)
+        if (a:lnum == 1)
+            let l0 = ''
+        else
+            let l0 = getline(a:lnum-1)
+        endif
+        " keep track of fenced code blocks
+        if l0 =~ '````*' || l0 =~ '~~~~*'
+            if b:fenced_block == 0
+                let b:fenced_block = 1
+            elseif b:fenced_block == 1
+                let b:fenced_block = 0
+            endif
+        endif
+
         let l2 = getline(a:lnum+1)
         if  l2 =~ '^==\+\s*' && !s:is_mkdCode(a:lnum+1)
             " next line is underlined (level 1)
@@ -58,16 +72,22 @@ else
 
         let l1 = getline(a:lnum)
         if l1 =~ '^#' && !s:is_mkdCode(a:lnum)
-            " don't include the section title in the fold
-            return '-1'
+            " fold level according to option
+            " (in vim -1 is visible, >= 0 is folded)
+            let l:level = matchend(l1, '^#\+')
+            if g:vim_markdown_folding_level == 1 || l:level > g:vim_markdown_folding_level
+                return -1
+            else
+                " code blocks are always folded
+                return b:fenced_block
+            endif
         endif
 
-        if (a:lnum == 1)
-            let l0 = ''
-        else
-            let l0 = getline(a:lnum-1)
-        endif
         if l0 =~ '^#' && !s:is_mkdCode(a:lnum-1)
+            " collapse comments in fenced code blocks into a single fold
+            if b:fenced_block == 1
+                return 1
+            endif
             " current line starts with hashes
             return '>'.matchend(l0, '^#\+')
         else
@@ -77,6 +97,10 @@ else
     endfunction
 endif
 
+
+let b:fenced_block = 0
+let g:vim_markdown_folding_level = get(g:, "vim_markdown_folding_level", 1)
+
 if !get(g:, "vim_markdown_folding_disabled", 0)
     setlocal foldexpr=Foldexpr_markdown(v:lnum)
     setlocal foldmethod=expr
diff --git a/ftplugin/markdown.vim b/ftplugin/markdown.vim
index f68e54c..bc916ef 100644
--- a/ftplugin/markdown.vim
+++ b/ftplugin/markdown.vim
@@ -302,12 +302,32 @@ function! s:Toc(...)
         let l:window_type = 'vertical'
     endif
 
-    try
-        silent lvimgrep /\(^\S.*\(\n[=-]\+\n\)\@=\|^#\+\)/ %
-    catch /E480/
+
+    let b:bufnr = bufnr('%')
+    let b:fenced_block = 0
+    let b:header_list = []
+    let l:header_max_len = 0
+    for i in range(1, line('$'))
+        let l:lineraw = getline(i)
+        let l:line = substitute(l:lineraw, "#", "\\\#", "g")
+        if l:line =~ '````*' || l:line =~ '\~\~\~\~*'
+            if b:fenced_block == 0
+                let b:fenced_block = 1
+            elseif b:fenced_block == 1
+                let b:fenced_block = 0
+            endif
+        endif
+        if l:line =~ '^#\+' && b:fenced_block == 0
+            " append line to location list
+            let b:item = {'lnum': i, 'text': l:line, 'valid': 1, 'bufnr': b:bufnr, 'col': 1}
+            let b:header_list = b:header_list + [b:item]
+        endif
+    endfor
+    if len(b:header_list) == 0
         echom "Toc: No headers."
         return
-    endtry
+    endif
+    call setloclist(0, b:header_list)
 
     if l:window_type ==# 'horizontal'
         lopen
-- 
2.39.5