Only include syntax files once

Avoids errors when including more than once, e.g. including vim twice
causes errors

diff --git a/plugin/mkd.vim b/plugin/mkd.vim
index 50bf9a71e6bb03d7c32ef6445eae276d4959aaec..4542ced52f9693021ba1f0938c6ce9c86eb7aee0 100644 (file)
--- a/plugin/mkd.vim
+++ b/plugin/mkd.vim
@@ -1,30 +1,34 @@
-" Completely stolen from vim-notes - http://peterodding.com/code/vim/notes/
-function! s:Markdown_highlight_sources(force)
+" Heavily based on vim-notes - http://peterodding.com/code/vim/notes/
+function! s:Markdown_highlight_sources()
     " Syntax highlight source code embedded in notes.
     " Look for code blocks in the current file
     let filetypes = {}
     for line in getline(1, '$')
-        let ft = matchstr(line, '```\zs\w\+\>')
-        if ft !~ '^\d*$' | let filetypes[ft] = 1 | endif
+        let ft = matchstr(line, '```\zs\w*\>')
+        if !empty(ft) && ft !~ '^\d*$' | let filetypes[ft] = 1 | endif
     endfor
-    " Don't refresh the highlighting if nothing has changed.
-    if !a:force && exists('b:mkd_previous_sources') && b:mkd_previous_sources == filetypes
+    if !exists('b:mkd_known_filetypes')
+        let b:mkd_known_filetypes = {}
+    endif
+    if b:mkd_known_filetypes == filetypes || empty(filetypes)
         return
-    else
-        let b:mkd_previous_sources = filetypes
     endif
+
     " Now we're ready to actually highlight the code blocks.
-    if !empty(filetypes)
-        let startgroup = 'mkdCodeStart'
-        let endgroup = 'mkdCodeEnd'
-        for ft in keys(filetypes)
+    let startgroup = 'mkdCodeStart'
+    let endgroup = 'mkdCodeEnd'
+    for ft in keys(filetypes)
+        if !has_key(b:mkd_known_filetypes, ft)
+
             let group = 'mkdSnippet' . toupper(ft)
             let include = s:syntax_include(ft)
-            let command = 'syntax region %s matchgroup=%s start="^```%s$" matchgroup=%s end="^```$" keepend contains=%s%s'
+            let command = 'syntax region %s matchgroup=%s start="```%s" matchgroup=%s end="```" keepend contains=%s%s'
             execute printf(command, group, startgroup, ft, endgroup, include, has('conceal') ? ' concealends' : '')
             execute printf('syntax cluster mkdNonListItem add=%s', group)
-        endfor
-    endif
+
+            let b:mkd_known_filetypes[ft] = 1
+        endif
+    endfor
 endfunction
 
 function! s:syntax_include(filetype)
@@ -54,7 +58,7 @@ endfunction
 
 function! s:Markdown_refresh_syntax()
     if &filetype == 'mkd' && line('$') > 1
-        call s:Markdown_highlight_sources(0)
+        call s:Markdown_highlight_sources()
     endif
 endfunction
 
@@ -65,4 +69,3 @@ augroup Mkd
     au InsertEnter,InsertLeave * call s:Markdown_refresh_syntax()
     au CursorHold,CursorHoldI * call s:Markdown_refresh_syntax()
 augroup END
-