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+" Test for breakindent
+"
+" Note: if you get strange failures when adding new tests, it might be that
+" while the test is run, the breakindent cacheing gets in its way.
+" It helps to change the tabastop setting and force a redraw (e.g. see
+" Test_breakindent08())
+if !exists('+breakindent')
+  finish
+endif
+
+let s:input ="\tabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOP"
+
+function s:screenline(lnum, width) abort
+  " always get 4 screen lines
+  redraw!
+  let line = []
+  for j in range(3)
+    for c in range(1, a:width)
+  call add(line, nr2char(screenchar(a:lnum+j, c)))
+    endfor
+    call add(line, "\n")
+  endfor
+  return join(line, '')
+endfunction
+
+function s:testwindows(...)
+  10new
+  vsp
+  vert resize 20
+  setl ts=4 sw=4 sts=4 breakindent 
+  put =s:input
+  if a:0
+    exe a:1
+  endif
+endfunction
+
+function s:close_windows(...)
+  bw!
+  if a:0
+    exe a:1
+  endif
+  unlet! g:line g:expect
+endfunction
+
+function Test_breakindent01()
+  " simple breakindent test
+  call s:testwindows('setl briopt=min:0')
+  let g:line=s:screenline(line('.'),8)
+  let g:expect="    abcd\n    qrst\n    GHIJ\n"
+  call assert_equal(g:expect, g:line)
+  call s:close_windows()
+endfunction
+
+function Test_breakindent02()
+  " simple breakindent test with showbreak set
+  call s:testwindows('setl briopt=min:0 sbr=>>')
+  let g:line=s:screenline(line('.'),8)
+  let g:expect="    abcd\n    >>qr\n    >>EF\n"
+  call assert_equal(g:expect, g:line)
+  call s:close_windows('set sbr=')
+endfunction
+
+function Test_breakindent03()
+  " simple breakindent test with showbreak set and briopt including sbr
+  call s:testwindows('setl briopt=sbr,min:0 sbr=++')
+  let g:line=s:screenline(line('.'),8)
+  let g:expect="    abcd\n++  qrst\n++  GHIJ\n"
+  call assert_equal(g:expect, g:line)
+  " clean up
+  call s:close_windows('set sbr=')
+endfunction
+
+function Test_breakindent04()
+  " breakindent set with min width 18
+  call s:testwindows('setl sbr= briopt=min:18')
+  let g:line=s:screenline(line('.'),8)
+  let g:expect="    abcd\n  qrstuv\n  IJKLMN\n"
+  call assert_equal(g:expect, g:line)
+  " clean up
+  call s:close_windows('set sbr=')
+endfunction
+
+function Test_breakindent05()
+  " breakindent set and shift by 2
+  call s:testwindows('setl briopt=shift:2,min:0')
+  let g:line=s:screenline(line('.'),8)
+  let g:expect="    abcd\n      qr\n      EF\n"
+  call assert_equal(g:expect, g:line)
+  call s:close_windows()
+endfunction
+
+function Test_breakindent06()
+  " breakindent set and shift by -1
+  call s:testwindows('setl briopt=shift:-1,min:0')
+  let g:line=s:screenline(line('.'),8)
+  let g:expect="    abcd\n   qrstu\n   HIJKL\n"
+  call assert_equal(g:expect, g:line)
+  call s:close_windows()
+endfunction
+
+function Test_breakindent07()
+  " breakindent set and shift by 1, Number  set sbr=? and briopt:sbr
+  call s:testwindows('setl briopt=shift:1,sbr,min:0 nu sbr=? nuw=4 cpo+=n')
+  let g:line=s:screenline(line('.'),10)
+  let g:expect="  2     ab\n?        m\n?        x\n"
+  call assert_equal(g:expect, g:line)
+  " clean up
+  call s:close_windows('set sbr= cpo-=n')
+endfunction
+
+function Test_breakindent07a()
+  " breakindent set and shift by 1, Number  set sbr=? and briopt:sbr
+  call s:testwindows('setl briopt=shift:1,sbr,min:0 nu sbr=? nuw=4')
+  let g:line=s:screenline(line('.'),10)
+  let g:expect="  2     ab\n    ?    m\n    ?    x\n"
+  call assert_equal(g:expect, g:line)
+  " clean up
+  call s:close_windows('set sbr=')
+endfunction
+
+function Test_breakindent08()
+  " breakindent set and shift by 1, Number and list set sbr=# and briopt:sbr
+  call s:testwindows('setl briopt=shift:1,sbr,min:0 nu nuw=4 sbr=# list cpo+=n ts=4')
+  " make sure, cache is invalidated!
+  set ts=8
+  redraw!
+  set ts=4
+  redraw!
+  let g:line=s:screenline(line('.'),10)
+  let g:expect="  2 ^Iabcd\n#      opq\n#      BCD\n"
+  call assert_equal(g:expect, g:line)
+  call s:close_windows('set sbr= cpo-=n')
+endfunction
+
+function Test_breakindent08a()
+  " breakindent set and shift by 1, Number and list set sbr=# and briopt:sbr
+  call s:testwindows('setl briopt=shift:1,sbr,min:0 nu nuw=4 sbr=# list')
+  let g:line=s:screenline(line('.'),10)
+  let g:expect="  2 ^Iabcd\n    #  opq\n    #  BCD\n"
+  call assert_equal(g:expect, g:line)
+  call s:close_windows('set sbr=')
+endfunction
+
+function Test_breakindent09()
+  " breakindent set and shift by 1, Number and list set sbr=#
+  call s:testwindows('setl briopt=shift:1,min:0 nu nuw=4 sbr=# list')
+  let g:line=s:screenline(line('.'),10)
+  let g:expect="  2 ^Iabcd\n       #op\n       #AB\n"
+  call assert_equal(g:expect, g:line)
+  call s:close_windows('set sbr=')
+endfunction
+
+function Test_breakindent10()
+  " breakindent set, Number set sbr=~
+  call s:testwindows('setl cpo+=n sbr=~ nu nuw=4 nolist briopt=sbr,min:0')
+  " make sure, cache is invalidated!
+  set ts=8
+  redraw!
+  set ts=4
+  redraw!
+  let g:line=s:screenline(line('.'),10)
+  let g:expect="  2     ab\n~       mn\n~       yz\n"
+  call assert_equal(g:expect, g:line)
+  call s:close_windows('set sbr= cpo-=n')
+endfunction
+
+function Test_breakindent11()
+  " test strdisplaywidth()
+  call s:testwindows('setl cpo-=n sbr=>> nu nuw=4 nolist briopt= ts=4')
+  let text=getline(2)
+  let width = strlen(text[1:])+indent(2)+strlen(&sbr)*3 " text wraps 3 times
+  call assert_equal(width, strdisplaywidth(text))
+  call s:close_windows('set sbr=')
+endfunction
+
+function Test_breakindent12()
+  " test breakindent with long indent
+  let s:input="\t\t\t\t\t{"
+  call s:testwindows('setl breakindent linebreak briopt=min:10 nu numberwidth=3 ts=4 list listchars=tab:>-')
+  let g:line=s:screenline(2,16)
+  let g:expect=" 2 >--->--->--->\n          ---{  \n~               \n"
+  call assert_equal(g:expect, g:line)
+  call s:close_windows('set nuw=4 listchars=')
+endfunction
+
+function Test_breakindent13()
+  let s:input=""
+  call s:testwindows('setl breakindent briopt=min:10 ts=8')
+  vert resize 20
+  call setline(1, ["    a\tb\tc\td\te", "    z   y       x       w       v"])
+  1
+  norm! fbgj"ayl
+  2
+  norm! fygj"byl
+  call assert_equal('d', @a)
+  call assert_equal('w', @b)
+  call s:close_windows()
+endfunction
+
+function Test_breakindent14()
+  let s:input=""
+  call s:testwindows('setl breakindent briopt= ts=8')
+  vert resize 30
+  norm! 3a1234567890
+  norm! a    abcde
+  exec "norm! 0\<C-V>tex"
+  let g:line=s:screenline(line('.'),8)
+  let g:expect="e       \n~       \n~       \n"
+  call assert_equal(g:expect, g:line)
+  call s:close_windows()
+endfunction
+
+function Test_breakindent15()
+  let s:input=""
+  call s:testwindows('setl breakindent briopt= ts=8 sw=8')
+  vert resize 30
+  norm! 4a1234567890
+  exe "normal! >>\<C-V>3f0x"
+  let g:line=s:screenline(line('.'),20)
+  let g:expect="        1234567890  \n~                   \n~                   \n"
+  call assert_equal(g:expect, g:line)
+  call s:close_windows()
+endfunction
+
+function Test_breakindent16()
+  " Check that overlong lines are indented correctly.
+  " TODO: currently it does not fail even when the bug is not fixed.
+  let s:input=""
+  call s:testwindows('setl breakindent briopt=min:0 ts=4')
+  call setline(1, "\t".repeat("1234567890", 10))
+  resize 6
+  norm! 1gg$
+  redraw!
+  let g:line=s:screenline(1,10)
+  let g:expect="    123456\n    789012\n    345678\n"
+  call assert_equal(g:expect, g:line)
+  let g:line=s:screenline(4,10)
+  let g:expect="    901234\n    567890\n    123456\n"
+  call assert_equal(g:expect, g:line)
+  call s:close_windows()
+endfunction