patch 9.1.1284: not possible to configure pum truncation char

Problem:  not possible to configure the completion menu truncation
          character
Solution: add the "trunc" suboption to the 'fillchars' setting to
          configure the truncation indicator (glepnir).

closes: #17006

Co-authored-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: glepnir <glephunter@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_popup.vim b/src/testdir/test_popup.vim
index 445a2be..d282f91 100644
--- a/src/testdir/test_popup.vim
+++ b/src/testdir/test_popup.vim
@@ -2018,8 +2018,9 @@
   call term_sendkeys(buf, "\<Esc>3Gdd\"zp")
 
   call term_sendkeys(buf, ":set lines=10 columns=32\<CR>")
+  call TermWait(buf, 50)
   call term_sendkeys(buf, "GA\<C-N>")
-  call VerifyScreenDump(buf, 'Test_pum_maxwidth_09', {'rows': 10, 'cols': 32})
+  call VerifyScreenDump(buf, 'Test_pum_maxwidth_05', {'rows': 10, 'cols': 32})
   call term_sendkeys(buf, "\<Esc>3Gdd\"zp")
 
   call StopVimInTerminal(buf)
@@ -2029,106 +2030,129 @@
   CheckScreendump
 
   let lines =<< trim END
+    let g:change = 0
     func Omni_test(findstart, base)
       if a:findstart
         return col(".")
       endif
-      return [
-        \ #{word: "123456789_123456789_123456789_"},
-        \ #{word: "一二三四五六七八九十"},
-        \ #{word: "abcdefghij"},
-        \ #{word: "上下左右"},
-        \ ]
+      if g:change == 0
+        return [
+          \ #{word: "123456789_123456789_123456789_"},
+          \ #{word: "一二三四五六七八九十"},
+          \ #{word: "abcdefghij"},
+          \ #{word: "上下左右"},
+          \ ]
+      elseif g:change == 1
+        return [
+          \ #{word: "foo", menu: "fooMenu", kind: "fooKind"},
+          \ #{word: "bar", menu: "barMenu", kind: "barKind"},
+          \ #{word: "baz", menu: "bazMenu", kind: "bazKind"},
+          \ ]
+      elseif g:change == 2
+        return [
+          \ #{word: "foo", menu: "fooMenu", kind: "fooKind"},
+          \ #{word: "bar", menu: "fooMenu", kind: "一二三四"},
+          \ #{word: "一二三四五", kind: "multi"},
+          \ ]
+      else
+        return [#{word: "bar", menu: "fooMenu", kind: "一二三"}]
+      endif
     endfunc
     set omnifunc=Omni_test
+    set cot+=menuone
   END
   call writefile(lines, 'Xtest', 'D')
   let  buf = RunVimInTerminal('-S Xtest', {})
   call TermWait(buf)
 
   call term_sendkeys(buf, "S\<C-X>\<C-O>")
-  call VerifyScreenDump(buf, 'Test_pum_maxwidth_05', {'rows': 8})
+  call VerifyScreenDump(buf, 'Test_pum_maxwidth_06', {'rows': 8})
   call term_sendkeys(buf, "\<ESC>")
 
   call term_sendkeys(buf, ":set pummaxwidth=10\<CR>")
   call term_sendkeys(buf, "S\<C-X>\<C-O>")
-  call VerifyScreenDump(buf, 'Test_pum_maxwidth_06', {'rows': 8})
+  call VerifyScreenDump(buf, 'Test_pum_maxwidth_07', {'rows': 8})
   call term_sendkeys(buf, "\<ESC>")
 
   if has('rightleft')
     call term_sendkeys(buf, ":set rightleft\<CR>")
     call term_sendkeys(buf, "S\<C-X>\<C-O>")
-    call VerifyScreenDump(buf, 'Test_pum_maxwidth_07', {'rows': 8})
+    call VerifyScreenDump(buf, 'Test_pum_maxwidth_08', {'rows': 8})
     call term_sendkeys(buf, "\<Esc>:set norightleft\<CR>")
   endif
 
   call term_sendkeys(buf, ":set pummaxwidth=2\<CR>")
   call term_sendkeys(buf, "S\<C-X>\<C-O>")
-  call VerifyScreenDump(buf, 'Test_pum_maxwidth_08', {'rows': 8})
+  call VerifyScreenDump(buf, 'Test_pum_maxwidth_09', {'rows': 8})
   call term_sendkeys(buf, "\<ESC>")
 
-  call StopVimInTerminal(buf)
-endfunc
+  call term_sendkeys(buf, ":set pummaxwidth=14\<CR>")
+  call term_sendkeys(buf, ":let g:change=1\<CR>S\<C-X>\<C-O>")
+  call VerifyScreenDump(buf, 'Test_pum_maxwidth_10', {'rows': 8})
+  call term_sendkeys(buf, "\<ESC>")
 
-func Test_pum_maxwidth_with_many_items()
-  CheckScreendump
-
-  let lines =<< trim END
-    func Omni_test(findstart, base)
-    if a:findstart
-      return col(".")
-    endif
-    return [
-      \ #{word: "foo", menu: "fooMenu", kind: "fooKind"},
-      \ #{word: "bar", menu: "barMenu", kind: "barKind"},
-      \ #{word: "baz", menu: "bazMenu", kind: "bazKind"},
-      \ ]
-    endfunc
-    set omnifunc=Omni_test
-  END
-  call writefile(lines, 'Xtest', 'D')
-  let  buf = RunVimInTerminal('-S Xtest', {})
-  call TermWait(buf)
-
-  call term_sendkeys(buf, ":set pummaxwidth=20\<CR>")
+  " Unicode Character U+2026 but one cell
+  call term_sendkeys(buf, ":set fcs+=trunc:…\<CR>")
   call term_sendkeys(buf, "S\<C-X>\<C-O>")
-  call VerifyScreenDump(buf, 'Test_pum_maxwidth_with_many_items_01', {'rows': 8})
+  call VerifyScreenDump(buf, 'Test_pum_maxwidth_11', {'rows': 8})
   call term_sendkeys(buf, "\<ESC>")
 
-  call term_sendkeys(buf, ":set pummaxwidth=19\<CR>")
-  call term_sendkeys(buf, "S\<C-X>\<C-O>")
-  call VerifyScreenDump(buf, 'Test_pum_maxwidth_with_many_items_02', {'rows': 8})
+  call term_sendkeys(buf, ":let g:change=2\<CR>S\<C-X>\<C-O>")
+  call VerifyScreenDump(buf, 'Test_pum_maxwidth_12', {'rows': 8})
   call term_sendkeys(buf, "\<ESC>")
 
-  call term_sendkeys(buf, ":set pummaxwidth=18\<CR>")   " display Ellipsis
+  call term_sendkeys(buf, ":set fcs&\<CR>")
   call term_sendkeys(buf, "S\<C-X>\<C-O>")
-  call VerifyScreenDump(buf, 'Test_pum_maxwidth_with_many_items_03', {'rows': 8})
+  call VerifyScreenDump(buf, 'Test_pum_maxwidth_13', {'rows': 8})
   call term_sendkeys(buf, "\<ESC>")
 
-  call term_sendkeys(buf, ":set pummaxwidth=16\<CR>")   " display Ellipsis
+  call term_sendkeys(buf, ":set fcs=trunc:_\<CR>")
+  call term_sendkeys(buf, ":let g:change=1\<CR>")
+  call TermWait(buf, 50)
   call term_sendkeys(buf, "S\<C-X>\<C-O>")
-  call VerifyScreenDump(buf, 'Test_pum_maxwidth_with_many_items_04', {'rows': 8})
+  call VerifyScreenDump(buf, 'Test_pum_maxwidth_14', {'rows': 8})
+  call term_sendkeys(buf, "\<ESC>")
+  call term_sendkeys(buf, ":set fcs&\<CR>")
+
+  if has('rightleft')
+    call term_sendkeys(buf, ":set rightleft\<CR>")
+    call term_sendkeys(buf, "S\<C-X>\<C-O>")
+    call VerifyScreenDump(buf, 'Test_pum_maxwidth_15', {'rows': 8})
+    call term_sendkeys(buf, "\<ESC>")
+
+    call term_sendkeys(buf, ":let g:change=2\<CR>")
+    call TermWait(buf, 50)
+    call term_sendkeys(buf, "S\<C-X>\<C-O>")
+    call VerifyScreenDump(buf, 'Test_pum_maxwidth_16', {'rows': 8})
+    call term_sendkeys(buf, "\<ESC>")
+
+    call term_sendkeys(buf, ":set fcs+=trunc:…\<CR>")
+    call term_sendkeys(buf, "S\<C-X>\<C-O>")
+    call VerifyScreenDump(buf, 'Test_pum_maxwidth_17', {'rows': 8})
+    call term_sendkeys(buf, "\<ESC>")
+
+    call term_sendkeys(buf, ":set fcs&\<CR>")
+    call term_sendkeys(buf, ":let g:change=3\<CR>")
+    call TermWait(buf, 50)
+    call term_sendkeys(buf, "S\<C-X>\<C-O>")
+    call VerifyScreenDump(buf, 'Test_pum_maxwidth_18', {'rows': 8})
+    call term_sendkeys(buf, "\<Esc>:set norightleft\<CR>")
+  endif
+
+  call term_sendkeys(buf, ":set pummaxwidth=4\<CR>")
+  call term_sendkeys(buf, ":let g:change=2\<CR>")
+  call TermWait(buf, 50)
+  call term_sendkeys(buf, "S\<C-X>\<C-O>")
+  call VerifyScreenDump(buf, 'Test_pum_maxwidth_19', {'rows': 8})
   call term_sendkeys(buf, "\<ESC>")
 
-  call term_sendkeys(buf, ":set pummaxwidth=15\<CR>")
-  call term_sendkeys(buf, "S\<C-X>\<C-O>")
-  call VerifyScreenDump(buf, 'Test_pum_maxwidth_with_many_items_05', {'rows': 8})
-  call term_sendkeys(buf, "\<ESC>")
-
-  call term_sendkeys(buf, ":set pummaxwidth=12\<CR>")
-  call term_sendkeys(buf, "S\<C-X>\<C-O>")
-  call VerifyScreenDump(buf, 'Test_pum_maxwidth_with_many_items_06', {'rows': 8})
-  call term_sendkeys(buf, "\<ESC>")
-
-  call term_sendkeys(buf, ":set pummaxwidth=10\<CR>")   " display Ellipsis
-  call term_sendkeys(buf, "S\<C-X>\<C-O>")
-  call VerifyScreenDump(buf, 'Test_pum_maxwidth_with_many_items_07', {'rows': 8})
-  call term_sendkeys(buf, "\<ESC>")
-
-  call term_sendkeys(buf, ":set pummaxwidth=1\<CR>")
-  call term_sendkeys(buf, "S\<C-X>\<C-O>")
-  call VerifyScreenDump(buf, 'Test_pum_maxwidth_with_many_items_08', {'rows': 8})
-  call term_sendkeys(buf, "\<ESC>")
+  if has('rightleft')
+    call term_sendkeys(buf, ":set rightleft\<CR>")
+    call TermWait(buf, 50)
+    call term_sendkeys(buf, "S\<C-X>\<C-O>")
+    call VerifyScreenDump(buf, 'Test_pum_maxwidth_20', {'rows': 8})
+    call term_sendkeys(buf, "\<Esc>:set norightleft\<CR>")
+  endif
 
   call StopVimInTerminal(buf)
 endfunc