vim-patch:9.1.1224: cannot :put while keeping indent (#33076)

Problem:  cannot :put while keeping indent (Peter Aronoff)
Solution: add the :iput ex command (64-bitman)

fixes: vim/vim#16225
closes: vim/vim#16886

https://github.com/vim/vim/commit/e08f10a55c3f15b0b4af631908551d88ec4fe502

Cherry-pick test_put.vim changes from patch 8.2.1593.

N/A patches:
vim-patch:9.1.1213: cannot :put while keeping indent
vim-patch:9.1.1215: Patch 9.1.1213 has some issues

Co-authored-by: 64-bitman <60551350+64-bitman@users.noreply.github.com>
Co-authored-by: Hirohito Higashi <h.east.727@gmail.com>

7 files changed, 122 insertions, 14 deletions

diff --git a/runtime/doc/change.txt b/runtime/doc/change.txt
index f7cbf7fd36..3d71c3e032 100644
--- a/runtime/doc/change.txt
+++ b/runtime/doc/change.txt
@@ -1105,6 +1105,11 @@ inside of strings can change!  Also see 'softtabstop' option. >
 :[line]pu[t]! [x]	Put the text [from register x] before [line] (default
 			current line).
 
+							*:ip* *:iput*
+:[line]ip[ut] [x]	like |:put|, but adjust indent to the current line
+
+:[line]ip[ut]! [x]	like |:put|!, but adjust indent to the current line
+
 ["x]]p		    or					*]p* *]<MiddleMouse>*
 ["x]]<MiddleMouse>	Like "p", but adjust the indent to the current line.
 			Using the mouse only works when 'mouse' contains 'n'
diff --git a/runtime/doc/index.txt b/runtime/doc/index.txt
index b814b3be78..4744b24e84 100644
--- a/runtime/doc/index.txt
+++ b/runtime/doc/index.txt
@@ -1348,6 +1348,8 @@ tag		command		action ~
 |:inoreabbrev|	:inorea[bbrev]	like ":noreabbrev" but for Insert mode
 |:inoremenu|	:inoreme[nu]	like ":noremenu" but for Insert mode
 |:intro|	:int[ro]	print the introductory message
+|:iput|		:ip[ut]		like |:put|, but adjust the indent to the
+				current line
 |:isearch|	:is[earch]	list one line where identifier matches
 |:isplit|	:isp[lit]	split window and jump to definition of
 				identifier
diff --git a/runtime/doc/news.txt b/runtime/doc/news.txt
index 7bdacd73bf..ad1481e304 100644
--- a/runtime/doc/news.txt
+++ b/runtime/doc/news.txt
@@ -115,7 +115,7 @@ DIAGNOSTICS
 
 EDITOR
 
-• todo
+• |:iput| works like |:put| but adjusts indent.
 
 EVENTS
 
diff --git a/src/nvim/api/command.c b/src/nvim/api/command.c
index de83ff97f7..4b93f09c61 100644
--- a/src/nvim/api/command.c
+++ b/src/nvim/api/command.c
@@ -504,7 +504,9 @@ String nvim_cmd(uint64_t channel_id, Dict(cmd) *cmd, Dict(cmd_opts) *opts, Arena
     VALIDATE((regname != '='), "%s", "Cannot use register \"=", {
       goto end;
     });
-    VALIDATE(valid_yank_reg(regname, ea.cmdidx != CMD_put && !IS_USER_CMDIDX(ea.cmdidx)),
+    VALIDATE(valid_yank_reg(regname,
+                            (!IS_USER_CMDIDX(ea.cmdidx)
+                             && ea.cmdidx != CMD_put && ea.cmdidx != CMD_iput)),
              "Invalid register: \"%c", regname, {
       goto end;
     });
diff --git a/src/nvim/ex_cmds.lua b/src/nvim/ex_cmds.lua
index d68d5a9afa..34723b6102 100644
--- a/src/nvim/ex_cmds.lua
+++ b/src/nvim/ex_cmds.lua
@@ -1219,6 +1219,12 @@ M.cmds = {
     func = 'ex_intro',
   },
   {
+    command = 'iput',
+    flags = bit.bor(RANGE, WHOLEFOLD, BANG, REGSTR, TRLBAR, ZEROR, CMDWIN, LOCK_OK, MODIFY),
+    addr_type = 'ADDR_LINES',
+    func = 'ex_iput',
+  },
+  {
     command = 'isearch',
     flags = bit.bor(BANG, RANGE, DFLALL, WHOLEFOLD, EXTRA, CMDWIN, LOCK_OK),
     addr_type = 'ADDR_LINES',
diff --git a/src/nvim/ex_docmd.c b/src/nvim/ex_docmd.c
index 640c729e3b..6c5cca5d5c 100644
--- a/src/nvim/ex_docmd.c
+++ b/src/nvim/ex_docmd.c
@@ -1393,8 +1393,9 @@ static void parse_register(exarg_T *eap)
       // Do not allow register = for user commands
       && (!IS_USER_CMDIDX(eap->cmdidx) || *eap->arg != '=')
       && !((eap->argt & EX_COUNT) && ascii_isdigit(*eap->arg))) {
-    if (valid_yank_reg(*eap->arg, (eap->cmdidx != CMD_put
-                                   && !IS_USER_CMDIDX(eap->cmdidx)))) {
+    if (valid_yank_reg(*eap->arg,
+                       (!IS_USER_CMDIDX(eap->cmdidx)
+                        && eap->cmdidx != CMD_put && eap->cmdidx != CMD_iput))) {
       eap->regname = (uint8_t)(*eap->arg++);
       // for '=' register: accept the rest of the line as an expression
       if (eap->arg[-1] == '=' && eap->arg[0] != NUL) {
@@ -1752,7 +1753,7 @@ int execute_cmd(exarg_T *eap, CmdParseInfo *cmdinfo, bool preview)
 
   if (!MODIFIABLE(curbuf) && (eap->argt & EX_MODIFY)
       // allow :put in terminals
-      && !(curbuf->terminal && eap->cmdidx == CMD_put)) {
+      && !(curbuf->terminal && (eap->cmdidx == CMD_put || eap->cmdidx == CMD_iput))) {
     errormsg = _(e_modifiable);
     goto end;
   }
@@ -2155,7 +2156,7 @@ static char *do_one_cmd(char **cmdlinep, int flags, cstack_T *cstack, LineGetter
     }
     if (!MODIFIABLE(curbuf) && (ea.argt & EX_MODIFY)
         // allow :put in terminals
-        && (!curbuf->terminal || ea.cmdidx != CMD_put)) {
+        && !(curbuf->terminal && (ea.cmdidx == CMD_put || ea.cmdidx == CMD_iput))) {
       // Command not allowed in non-'modifiable' buffer
       errormsg = _(e_modifiable);
       goto doend;
@@ -6306,6 +6307,20 @@ static void ex_put(exarg_T *eap)
          PUT_LINE|PUT_CURSLINE);
 }
 
+/// ":iput".
+static void ex_iput(exarg_T *eap)
+{
+  // ":0iput" works like ":1iput!".
+  if (eap->line2 == 0) {
+    eap->line2 = 1;
+    eap->forceit = true;
+  }
+  curwin->w_cursor.lnum = eap->line2;
+  check_cursor_col(curwin);
+  do_put(eap->regname, NULL, eap->forceit ? BACKWARD : FORWARD, 1L,
+         PUT_LINE|PUT_CURSLINE|PUT_FIXINDENT);
+}
+
 /// Handle ":copy" and ":move".
 static void ex_copymove(exarg_T *eap)
 {
diff --git a/test/old/testdir/test_put.vim b/test/old/testdir/test_put.vim
index e0a78c7409..26eb7f0eb4 100644
--- a/test/old/testdir/test_put.vim
+++ b/test/old/testdir/test_put.vim
@@ -73,16 +73,18 @@ func Test_put_fails_when_nomodifiable()
   setlocal nomodifiable
 
   normal! yy
-  call assert_fails(':put', 'E21')
-  call assert_fails(':put!', 'E21')
-  call assert_fails(':normal! p', 'E21')
-  call assert_fails(':normal! gp', 'E21')
-  call assert_fails(':normal! P', 'E21')
-  call assert_fails(':normal! gP', 'E21')
+  call assert_fails(':put', 'E21:')
+  call assert_fails(':put!', 'E21:')
+  call assert_fails(':iput', 'E21:')
+  call assert_fails(':iput!', 'E21:')
+  call assert_fails(':normal! p', 'E21:')
+  call assert_fails(':normal! gp', 'E21:')
+  call assert_fails(':normal! P', 'E21:')
+  call assert_fails(':normal! gP', 'E21:')
 
   if has('mouse')
     set mouse=n
-    call assert_fails('execute "normal! \<MiddleMouse>"', 'E21')
+    call assert_fails('execute "normal! \<MiddleMouse>"', 'E21:')
     set mouse&
   endif
 
@@ -132,7 +134,7 @@ func Test_put_visual_delete_all_lines()
   let @r = ''
   normal! VG"rgp
   call assert_equal(1, line('$'))
-  close!
+  bw!
 endfunc
 
 func Test_gp_with_count_leaves_cursor_at_end()
@@ -328,6 +330,82 @@ func Test_put_list()
   bw!
 endfunc
 
+func Test_iput_multiline()
+  new
+  setlocal noexpandtab
+  call setline(1, "\<Tab>foo")
+  call setreg('0', "bar\n\<Tab>bar2\nbar3", 'l')
+  iput
+  call assert_equal(["\<Tab>bar", "\<Tab>\<Tab>bar2", "\<Tab>bar3"], getline(2, 4))
+  setlocal expandtab tabstop=8 shiftwidth=8 noshiftround
+  iput
+  call assert_equal([repeat(' ', 8) . "bar",
+        \ repeat(' ', 16) . "bar2",
+        \ repeat(' ', 8) . "bar3"], getline(5, 7))
+  bw!
+endfunc
+
+func Test_iput_beforeafter_tab()
+  new
+  setlocal noexpandtab
+  call setline(1, "\<Tab>foo")
+  call setreg('0', "bar", 'l')
+  iput
+  call assert_equal(["\<Tab>bar"], getline(2, '$'))
+  call feedkeys("k", 'x')
+  iput!
+  call assert_equal("\<Tab>bar", getline(1))
+  call assert_equal("\<Tab>bar", getline(3))
+  bw!
+endfunc
+
+func Test_iput_beforeafter_expandtab()
+  new
+  setlocal expandtab tabstop=8 shiftwidth=8 noshiftround
+  call setline(1, "\<Tab>foo")
+  call setreg('0', "bar", 'l')
+  iput
+  call assert_equal([repeat(' ', 8) . "bar"], getline(2, '$'))
+  :1iput!
+  call assert_equal(repeat(' ', 8) . "bar", getline(1))
+  bw!
+endfunc
+
+func Test_iput_invalidrange()
+  new
+  call setreg('0', "bar", 'l')
+  call assert_fails(':10iput', 'E16:')
+  bw!
+endfunc
+
+func Test_iput_zero_range()
+  new
+  let _var = [getreg('a'), getregtype('a')]
+  call setreg('a', 'foobar', 'l')
+  call setline(1, range(1, 2))
+  call cursor(1, 1)
+  0iput a
+  call assert_equal(['foobar', '1', '2'], getline(1, '$'))
+  %d
+  call setline(1, range(1, 2))
+  call cursor(1, 1)
+  0iput! a
+  call assert_equal(['foobar', '1', '2'], getline(1, '$'))
+  call setreg('a', _var[0], _var[1])
+  bw!
+endfunc
+
+func Test_iput_not_put()
+  new
+  call setline(1, "\<Tab>foo")
+  call setreg('0', "bar", 'l')
+  iput
+  call assert_equal("\<Tab>bar", getline(2))
+  put
+  call assert_equal("bar", getline(3))
+  bw!
+endfunc
+
 " Test pasting the '.' register
 func Test_put_inserted()
   new