Fix indent of \[ \] pairs (#307)

indent/tex.vim

@@ -88,6 +88,14 @@ function! VimtexIndent() " {{{1
     endif
   endif
 
+  " Add/Subtract indent on begin/end displayed equation
+  if pline =~# '\\\[\s*$'
+    let ind = ind + &sw
+  endif
+  if pline =~# '\\\]\s*$'
+    let ind = ind - &sw
+  endif
+
   " Indent opening and closing delimiters
   let l:delimiters = match(map(synstack(v:lnum, max([col('.') - 1, 1])),
         \ 'synIDattr(v:val, ''name'')'), '^texMathZone') >= 0
@@ -144,15 +152,11 @@ let s:delimiters_open_tex = '\(' . join([
         \ '{',
         \ '\[',
         \ '\\(',
-        \ '\\\[',
-        \ '\\\Cbegin\s*{.\{-}}',
       \ ], '\|') . '\)'
 let s:delimiters_close_tex = '\(' . join([
         \ '}',
         \ '\]',
         \ '\\)',
-        \ '\\\]',
-        \ '\\\Cend\s*{.\{-}}',
       \ ], '\|') . '\)'
 let s:delimiters_open_math = '\(' . join([
         \ '\\{',

test/feature/indentation/main.tex

@@ -6,6 +6,10 @@
 \tikz \fill[green] rectangle (0.5,0.5); Something
 about something.
 
+\[
+  1+1
+\]
+
 \begin{align}
   2+2=4
 \end{align}
@@ -16,10 +20,11 @@ about something.
 \end{itemize}
 
 \begin{equation}
-  \left\{
+  \left.
-    asdasd
+    f(x) = 3
-  \right\}
+  \right.
 \end{equation}
+
 {
   asdasd
 }