vim-patch:8.2.4242: put in Visual mode cannot be repeated

Problem:    Put in Visual mode cannot be repeated.
Solution:   Use "P" to put without yanking the deleted text into the unnamed
            register. (Shougo Matsushita, closes vim/vim#9591)
https://github.com/vim/vim/commit/fb55207ed17918c8a2a6cadf5ad9d5fcf686a7ab

Cherry-pick get_y_previous() and set_y_previous() from patch 8.1.1736.
Nvim has removed y_current, so code related to it is N/A.

5 files changed, 56 insertions, 9 deletions

diff --git a/runtime/doc/visual.txt b/runtime/doc/visual.txt
index 5563a56216..4d5366a41a 100644
--- a/runtime/doc/visual.txt
+++ b/runtime/doc/visual.txt
@@ -255,6 +255,7 @@ Additionally the following commands can be used:
 	X	delete (2)					|v_X|
 	Y	yank (2)					|v_Y|
 	p	put						|v_p|
+	P	put without unnamed register overwrite		|v_P|
 	J	join (1)					|v_J|
 	U	make uppercase					|v_U|
 	u	make lowercase					|v_u|
diff --git a/src/nvim/normal.c b/src/nvim/normal.c
index 225c66aae1..21c465434a 100644
--- a/src/nvim/normal.c
+++ b/src/nvim/normal.c
@@ -7509,9 +7509,9 @@ static void nv_put_opt(cmdarg_T *cap, bool fix_indent)
       // overwrites if the old contents is being put.
       was_visual = true;
       regname = cap->oap->regname;
+      bool save_unnamed = cap->cmdchar == 'P';
       // '+' and '*' could be the same selection
-      bool clipoverwrite = (regname == '+' || regname == '*')
-                           && (cb_flags & CB_UNNAMEDMASK);
+      bool clipoverwrite = (regname == '+' || regname == '*') && (cb_flags & CB_UNNAMEDMASK);
       if (regname == 0 || regname == '"' || clipoverwrite
           || ascii_isdigit(regname) || regname == '-') {
         // The delete might overwrite the register we want to put, save it first
@@ -7524,6 +7524,10 @@ static void nv_put_opt(cmdarg_T *cap, bool fix_indent)
       // do_put(), which requires the visual selection to still be active.
       if (!VIsual_active || VIsual_mode == 'V' || regname != '.') {
         // Now delete the selected text. Avoid messages here.
+        yankreg_T *old_y_previous;
+        if (save_unnamed) {
+          old_y_previous = get_y_previous();
+        }
         cap->cmdchar = 'd';
         cap->nchar = NUL;
         cap->oap->regname = NUL;
@@ -7533,6 +7537,10 @@ static void nv_put_opt(cmdarg_T *cap, bool fix_indent)
         empty = (curbuf->b_ml.ml_flags & ML_EMPTY);
         msg_silent--;
 
+        if (save_unnamed) {
+          set_y_previous(old_y_previous);
+        }
+
         // delete PUT_LINE_BACKWARD;
         cap->oap->regname = regname;
       }
diff --git a/src/nvim/ops.c b/src/nvim/ops.c
index b8b639265c..f8ab6b2556 100644
--- a/src/nvim/ops.c
+++ b/src/nvim/ops.c
@@ -135,10 +135,18 @@ static char opchars[][3] =
   { Ctrl_X, NUL, OPF_CHANGE },           // OP_NR_SUB
 };
 
-/*
- * Translate a command name into an operator type.
- * Must only be called with a valid operator name!
- */
+yankreg_T *get_y_previous(void)
+{
+  return y_previous;
+}
+
+void set_y_previous(yankreg_T *yreg)
+{
+  y_previous = yreg;
+}
+
+/// Translate a command name into an operator type.
+/// Must only be called with a valid operator name!
 int get_op_type(int char1, int char2)
 {
   int i;
diff --git a/src/nvim/testdir/test_visual.vim b/src/nvim/testdir/test_visual.vim
index 76274fb038..e931e06175 100644
--- a/src/nvim/testdir/test_visual.vim
+++ b/src/nvim/testdir/test_visual.vim
@@ -1184,8 +1184,32 @@ func Test_visual_undo_deletes_last_line()
   exe "normal ggvjfxO"
   undo
   normal gNU
+
   bwipe!
 endfunc
 
+func Test_visual_paste()
+  new
+
+  " v_p overwrites unnamed register.
+  call setline(1, ['xxxx'])
+  call setreg('"', 'foo')
+  call setreg('-', 'bar')
+  normal 1Gvp
+  call assert_equal(@", 'x')
+  call assert_equal(@-, 'x')
+
+  if has('clipboard')
+    " v_P does not overwrite unnamed register.
+    call setline(1, ['xxxx'])
+    call setreg('"', 'foo')
+    call setreg('-', 'bar')
+    normal 1GvP
+    call assert_equal(@", 'foo')
+    call assert_equal(@-, 'x')
+  endif
+
+  bwipe!
+endfunc
 
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/test/functional/editor/put_spec.lua b/test/functional/editor/put_spec.lua
index fdda2be131..c367f8fdd0 100644
--- a/test/functional/editor/put_spec.lua
+++ b/test/functional/editor/put_spec.lua
@@ -507,7 +507,9 @@ describe('put command', function()
       return function(exception_table, after_redo)
         test_expect(exception_table, after_redo)
         if selection_string then
-          eq(selection_string, getreg('"'))
+          if not conversion_table.put_backwards then
+            eq(selection_string, getreg('"'))
+          end
         else
           eq('test_string"', getreg('"'))
         end
@@ -714,7 +716,9 @@ describe('put command', function()
             expect_base, conversion_table)
           return function(exception_table, after_redo)
             test_expect(exception_table, after_redo)
-            eq('Line of words 1\n', getreg('"'))
+            if not conversion_table.put_backwards then
+              eq('Line of words 1\n', getreg('"'))
+            end
           end
         end
         local base_expect_string = [[
@@ -748,7 +752,9 @@ describe('put command', function()
           end, expect_base, conversion_table)
         return function(e,c)
           test_expect(e,c)
-          eq('Lin\nLin', getreg('"'))
+          if not conversion_table.put_backwards then
+            eq('Lin\nLin', getreg('"'))
+          end
         end
       end