fix: problem with get_surrounding_delim

refer: #3207

Author: lervag

autoload/vimtex/delim.vim

@@ -491,37 +491,36 @@ function! s:get_surrounding_delim(type) abort " {{{1
   let l:save_pos = vimtex#pos#get_cursor()
   let l:pos_val_cursor = vimtex#pos#val(l:save_pos)
   let l:pos_val_last = l:pos_val_cursor
-  let l:pos_val_open = l:pos_val_cursor - 1
+  let l:pos_val_current = l:pos_val_cursor - 1
 
   let l:count = 0
-  while l:pos_val_open < l:pos_val_last && l:count < 100
+  while l:pos_val_current < l:pos_val_last && l:count < 100
     let l:count += 1
     let l:open = vimtex#delim#get_prev(a:type, 'open')
     if empty(l:open) | break | endif
 
     let l:env_close = vimtex#delim#get_next_after(l:open, 'env_all', 'close')
+    let l:env_open = vimtex#delim#get_matching(l:env_close)
+
+    let l:pos_val_open = vimtex#pos#val(l:open)
+    let l:pos_val_env_open = empty(l:env_open) ? 0 : vimtex#pos#val(l:env_open)
     let l:pos_val_env_close = empty(l:env_close)
           \ ? l:pos_val_cursor + 1
           \ : vimtex#pos#val(l:env_close) + strlen(l:env_close.match) - 1
-    if l:pos_val_env_close > l:pos_val_cursor
-      let l:close = vimtex#delim#get_matching(l:open)
 
-      let l:env_open = vimtex#delim#get_prev_before(l:close, 'env_all', 'open')
-      let l:pos_val_env_open = empty(l:env_open)
-            \ ? 0
-            \ : vimtex#pos#val(l:env_open)
-      if l:pos_val_env_open < l:pos_val_cursor
-        let l:pos_val_try = vimtex#pos#val(l:close) + strlen(l:close.match) - 1
-        if l:pos_val_try >= l:pos_val_cursor
-          call vimtex#pos#set_cursor(l:save_pos)
-          return [l:open, l:close]
-        endif
+    if l:pos_val_env_open > l:pos_val_open
+          \ || l:pos_val_env_close > l:pos_val_cursor
+      let l:close = vimtex#delim#get_matching(l:open)
+      let l:pos_val_try = vimtex#pos#val(l:close) + strlen(l:close.match) - 1
+      if l:pos_val_try >= l:pos_val_cursor
+        call vimtex#pos#set_cursor(l:save_pos)
+        return [l:open, l:close]
       endif
     endif
 
     call vimtex#pos#set_cursor(vimtex#pos#prev(l:open))
-    let l:pos_val_last = l:pos_val_open
-    let l:pos_val_open = vimtex#pos#val(l:open)
+    let l:pos_val_last = l:pos_val_current
+    let l:pos_val_current = l:pos_val_open
   endwhile
 
   call vimtex#pos#set_cursor(l:save_pos)

test/test-textobj/test-delims.vim

@@ -0,0 +1,60 @@
+set nocompatible
+let &rtp = '../..,' . &rtp
+filetype plugin on
+syntax on
+
+set nomore
+
+setfiletype tex
+
+call vimtex#test#keys('Edid',
+      \ '\caption{Testing easy.}',
+      \ '\caption{}'
+      \)
+
+call vimtex#test#keys('Edad',
+      \ '\caption{Testing easy.}',
+      \ '\caption'
+      \)
+
+call vimtex#test#keys('Edid',
+      \ '\caption{Testing {nested}.}',
+      \ '\caption{}'
+      \)
+
+call vimtex#test#keys('$bdid',
+      \ '\caption{Testing {nested} after}',
+      \ '\caption{}'
+      \)
+
+call vimtex#test#keys('Edid',
+      \ '\caption{Testing $math$.}',
+      \ '\caption{}'
+      \)
+
+call vimtex#test#keys('4jdid', [
+      \ 'An interval like',
+      \ '\begin{equation}',
+      \ '  I = (0, 1]',
+      \ '\end{equation}',
+      \ 'is called half-open, just like the interval',
+      \ '\[',
+      \ '  J = [0, 1)',
+      \ '\]',
+      \], [
+      \ 'An interval like',
+      \ '\begin{equation}',
+      \ '  I = (0, 1]',
+      \ '\end{equation}',
+      \ 'is called half-open, just like the interval',
+      \ '\[',
+      \ '  J = [0, 1)',
+      \ '\]',
+      \])
+
+call vimtex#test#keys('$bdid',
+      \ '\caption{Testing $math$ after}',
+      \ '\caption{}'
+      \)
+
+call vimtex#test#finished()