patch 8.0.0126
Problem:    Display problem with 'foldcolumn' and a wide character.
            (esiegerman)
Solution:   Don't use "extra" but an allocated buffer. (Christian Brabandt,
            closes #1310)
diff --git a/src/testdir/Make_all.mak b/src/testdir/Make_all.mak
index 17c70f3..c78e34b 100644
--- a/src/testdir/Make_all.mak
+++ b/src/testdir/Make_all.mak
@@ -148,6 +148,7 @@
 	    test_cscope.res \
 	    test_diffmode.res \
 	    test_digraph.res \
+	    test_display.res \
 	    test_farsi.res \
 	    test_fnameescape.res \
 	    test_gf.res \
diff --git a/src/testdir/test_display.vim b/src/testdir/test_display.vim
new file mode 100644
index 0000000..ba7b7d7
--- /dev/null
+++ b/src/testdir/test_display.vim
@@ -0,0 +1,37 @@
+" Test for displaying stuff
+if !has('gui_running') && has('unix')
+  set term=ansi
+endif
+
+function! s:screenline(lnum, nr) abort
+  let line = []
+  for j in range(a:nr)
+    for c in range(1, winwidth(0))
+        call add(line, nr2char(screenchar(a:lnum+j, c)))
+    endfor
+    call add(line, "\n")
+  endfor
+  return join(line, '')
+endfunction
+
+function! Test_display_foldcolumn()
+  new
+  vnew
+  vert resize 25
+
+  1put='e more noise blah blah‚ more stuff here'
+
+  let expect = "e more noise blah blah<82\n> more stuff here        \n"
+
+  call cursor(2, 1)
+  norm! zt
+  redraw!
+  call assert_equal(expect, s:screenline(1,2))
+  set fdc=2
+  redraw!
+  let expect = "  e more noise blah blah<\n  82> more stuff here    \n"
+  call assert_equal(expect, s:screenline(1,2))
+
+  quit!
+  quit!
+endfunction