patch 8.2.1022: various parts of code not covered by tests

Problem:    Various parts of code not covered by tests.
Solution:   Add more tests. (Yegappan Lakshmanan, closes #6300)

src/testdir/test_edit.vim

@@ -401,6 +401,14 @@ func Test_edit_13()
   call assert_equal("", getline(2))
   call assert_equal("    baz", getline(3))
   set autoindent&
+
+  " pressing <C-U> to erase line should keep the indent with 'autoindent'
+  set backspace=2 autoindent
+  %d
+  exe "normal i\tone\<CR>three\<C-U>two"
+  call assert_equal(["\tone", "\ttwo"], getline(1, '$'))
+  set backspace& autoindent&
+
   bwipe!
 endfunc
 
@@ -1301,9 +1309,7 @@ endfunc
 
 func Test_edit_rightleft()
   " Cursor in rightleft mode moves differently
-  if !exists("+rightleft")
-    return
-  endif
+  CheckFeature rightleft
   call NewWindow(10, 20)
   call setline(1, ['abc', 'def', 'ghi'])
   call cursor(1, 2)
@@ -1348,6 +1354,13 @@ func Test_edit_rightleft()
         \"                 ihg",
         \"                   ~"]
   call assert_equal(join(expect, "\n"), join(lines, "\n"))
+  %d _
+  call test_override('redraw_flag', 1)
+  call test_override('char_avail', 1)
+  call feedkeys("a\<C-V>x41", "xt")
+  redraw!
+  call assert_equal(repeat(' ', 19) .. 'A', Screenline(1))
+  call test_override('ALL', 0)
   set norightleft
   bw!
 endfunc
@@ -1683,4 +1696,103 @@ func Test_edit_file_no_read_perm()
   call delete('Xfile')
 endfunc
 
+" Pressing escape in 'insertmode' should beep
+func Test_edit_insertmode_esc_beeps()
+  new
+  set insertmode
+  call assert_beeps("call feedkeys(\"one\<Esc>\", 'xt')")
+  set insertmode&
+  " unsupported CTRL-G command should beep in insert mode.
+  call assert_beeps("normal i\<C-G>l")
+  close!
+endfunc
+
+" Test for 'hkmap' and 'hkmapp'
+func Test_edit_hkmap()
+  CheckFeature rightleft
+  if has('win32') && !has('gui')
+    " Test fails on the MS-Windows terminal version
+    return
+  endif
+  new
+
+  set revins hkmap
+  let str = 'abcdefghijklmnopqrstuvwxyz'
+  let str ..= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
+  let str ..= '`/'',.;'
+  call feedkeys('i' .. str, 'xt')
+  let expected = "óõú,.;"
+  let expected ..= "ZYXWVUTSRQPONMLKJIHGFEDCBA"
+  let expected ..= "æèñ'äåàãø/ôíîöêìçïéòë÷âáðù"
+  call assert_equal(expected, getline(1))
+
+  %d
+  set revins hkmap hkmapp
+  let str = 'abcdefghijklmnopqrstuvwxyz'
+  let str ..= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
+  call feedkeys('i' .. str, 'xt')
+  let expected = "õYXWVUTSRQóOïíLKJIHGFEDêBA"
+  let expected ..= "öòXùåèúæø'ôñðîì÷çéäâóǟãëáà"
+  call assert_equal(expected, getline(1))
+
+  set revins& hkmap& hkmapp&
+  close!
+endfunc
+
+" Test for 'allowrevins' and using CTRL-_ in insert mode
+func Test_edit_allowrevins()
+  CheckFeature rightleft
+  new
+  set allowrevins
+  call feedkeys("iABC\<C-_>DEF\<C-_>GHI", 'xt')
+  call assert_equal('ABCFEDGHI', getline(1))
+  set allowrevins&
+  close!
+endfunc
+
+" Test for inserting a register in insert mode using CTRL-R
+func Test_edit_insert_reg()
+  new
+  let g:Line = ''
+  func SaveFirstLine()
+    let g:Line = Screenline(1)
+    return 'r'
+  endfunc
+  inoremap <expr> <buffer> <F2> SaveFirstLine()
+  call test_override('redraw_flag', 1)
+  call test_override('char_avail', 1)
+  let @r = 'sample'
+  call feedkeys("a\<C-R>=SaveFirstLine()\<CR>", "xt")
+  call assert_equal('"', g:Line)
+  call test_override('ALL', 0)
+  close!
+endfunc
+
+" When a character is inserted at the last position of the last line in a
+" window, the window contents should be scrolled one line up. If the top line
+" is part of a fold, then the entire fold should be scrolled up.
+func Test_edit_lastline_scroll()
+  new
+  let h = winheight(0)
+  let lines = ['one', 'two', 'three']
+  let lines += repeat(['vim'], h - 4)
+  call setline(1, lines)
+  call setline(h, repeat('x', winwidth(0) - 1))
+  call feedkeys("GAx", 'xt')
+  redraw!
+  call assert_equal(h - 1, winline())
+  call assert_equal(2, line('w0'))
+
+  " scroll with a fold
+  1,2fold
+  normal gg
+  call setline(h + 1, repeat('x', winwidth(0) - 1))
+  call feedkeys("GAx", 'xt')
+  redraw!
+  call assert_equal(h - 1, winline())
+  call assert_equal(3, line('w0'))
+
+  close!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab