Compatibility improvements

autoload/pencil.vim

@@ -155,18 +155,30 @@ fun! pencil#init(...) abort
   elsei b:pencil_wrap_mode ==# s:WRAP_MODE_SOFT
     setl textwidth=0
     setl wrap
+
+    if has('linebreak')
       setl linebreak
       " TODO breakat not working yet with n and m-dash
       setl breakat-=*         " avoid breaking footnote*
       setl breakat-=@         " avoid breaking at email addresses
+    en
+
+    if has('syntax')
       setl colorcolumn=0      " doesn't align as expected
+    en
   el
     setl textwidth<
     setl wrap< nowrap<
+
+    if has('linebreak')
       setl linebreak< nolinebreak<
       setl breakat<
+    en
+
+    if has('syntax')
       setl colorcolumn<
     en
+  en
 
   if (  v:version > 704 ||
    \   (v:version ==# 704 && has('patch-7.4.338')))
@@ -191,6 +203,7 @@ fun! pencil#init(...) abort
   " because ve=onemore is relatively rare and could break
   " other plugins, restrict its presence to buffer
   " Better: restore ve to original setting
+  if has('virtualedit')
     if b:pencil_wrap_mode && get(l:args, 'cursorwrap', g:pencil#cursorwrap)
       set whichwrap+=<,>,b,s,h,l,[,]
       aug pencil_cursorwrap
@@ -200,6 +213,7 @@ fun! pencil#init(...) abort
     el
       sil! au! pencil_cursorwrap * <buffer>
     en
+  en
 
   " Because syntax for fenced code blocks will mess with the
   " definition of a word (via iskeyword) we'll impose a prose-
@@ -221,7 +235,11 @@ fun! pencil#init(...) abort
     setl nolist
     setl wrapmargin=0
     setl autoindent         " needed by formatoptions=n
+
+    if has('smartindent')
       setl nosmartindent      " avoid c-style indents in prose
+    en
+
     setl formatoptions+=n   " recognize numbered lists
     setl formatoptions+=1   " don't break line before 1 letter word
     setl formatoptions+=t   " autoformat of text (vim default)
@@ -245,15 +263,18 @@ fun! pencil#init(...) abort
         \ get(l:args, 'concealcursor', g:pencil#concealcursor)
     en
   el
+    if has('smartindent')
       setl smartindent< nosmartindent<
-    setl autoindent< noautoindent<
-    setl list< nolist<
-    setl wrapmargin<
-    setl formatoptions<
+    en
     if has('conceal')
       setl conceallevel<
       setl concealcursor<
     en
+
+    setl autoindent< noautoindent<
+    setl list< nolist<
+    setl wrapmargin<
+    setl formatoptions<
   en
 
   if b:pencil_wrap_mode ==# s:WRAP_MODE_SOFT