paste: one undo-block per stream

- All "chunks" in a paste-stream should form a single undo-block. Side
  effect of 7a85792884 was to create an undo-block for each chunk.
- Also: remove old :redraw force logic, irrelevant after 7a85792884.

runtime/doc/api.txt

@@ -829,11 +829,12 @@ nvim_put({lines}, {type}, {after}, {follow})                      *nvim_put()*
                 Parameters: ~
                     {lines}   |readfile()|-style list of lines.
                               |channel-lines|
-                    {type}    Edit behavior:
+                    {type}    Edit behavior: any |getregtype()| result, or:
-                              • "b" |blockwise-visual| mode
+                              • "b" |blockwise-visual| mode (may include
+                                width, e.g. "b3")
                               • "c" |characterwise| mode
                               • "l" |linewise| mode
-                              • "" guess by contents
+                              • "" guess by contents, see |setreg()|
                     {after}   Insert after cursor (like |p|), or before (like
                               |P|).
                     {follow}  Place cursor at end of inserted text.

src/nvim/api/vim.c

@@ -1293,11 +1293,11 @@ theend:
 /// Compare |:put| and |p| which are always linewise.
 ///
 /// @param lines  |readfile()|-style list of lines. |channel-lines|
-/// @param type  Edit behavior:
+/// @param type  Edit behavior: any |getregtype()| result, or:
-///              - "b" |blockwise-visual| mode
+///              - "b" |blockwise-visual| mode (may include width, e.g. "b3")
 ///              - "c" |characterwise| mode
 ///              - "l" |linewise| mode
-///              - ""  guess by contents
+///              - ""  guess by contents, see |setreg()|
 /// @param after  Insert after cursor (like |p|), or before (like |P|).
 /// @param follow  Place cursor at end of inserted text.
 /// @param[out] err Error details, if any

src/nvim/lua/vim.lua

@@ -175,13 +175,15 @@ end
 --@returns false if client should cancel the paste.
 local function paste(lines, phase) end  -- luacheck: no unused
 paste = (function()
-  local tdots, tredraw, tick, got_line1 = 0, 0, 0, false
+  local tdots, tick, got_line1 = 0, 0, false
   return function(lines, phase)
     local call = vim.api.nvim_call_function
     local now = vim.loop.now()
     local mode = call('mode', {}):sub(1,1)
     if phase < 2 then  -- Reset flags.
-      tdots, tredraw, tick, got_line1 = now, now, 0, false
+      tdots, tick, got_line1 = now, 0, false
+    elseif mode ~= 'c' then
+      vim.api.nvim_command('undojoin')
     end
     if mode == 'c' and not got_line1 then  -- cmdline-mode: paste only 1 line.
       got_line1 = (#lines > 1)
@@ -193,11 +195,6 @@ paste = (function()
     else
       vim.api.nvim_put(lines, 'c', true, true)
     end
-    if (now - tredraw >= 1000) or phase == -1 or phase > 2 then
-      tredraw = now
-      vim.api.nvim_command('redraw')
-      vim.api.nvim_command('redrawstatus')
-    end
     if phase ~= -1 and (now - tdots >= 100) then
       local dots = ('.'):rep(tick % 4)
       tdots = now

test/functional/api/vim_spec.lua

@@ -373,6 +373,35 @@ describe('API', function()
       expect_err('Invalid phase: 4', request,
         'nvim_paste', 'foo', true, 4)
     end)
+    it('stream: multiple chunks form one undo-block', function()
+      nvim('paste', '1/chunk 1 (start)\n', true, 1)
+      nvim('paste', '1/chunk 2 (end)\n', true, 3)
+      local expected1 = [[
+        1/chunk 1 (start)
+        1/chunk 2 (end)
+        ]]
+      expect(expected1)
+      nvim('paste', '2/chunk 1 (start)\n', true, 1)
+      nvim('paste', '2/chunk 2\n', true, 2)
+      expect([[
+        1/chunk 1 (start)
+        1/chunk 2 (end)
+        2/chunk 1 (start)
+        2/chunk 2
+        ]])
+      nvim('paste', '2/chunk 3\n', true, 2)
+      nvim('paste', '2/chunk 4 (end)\n', true, 3)
+      expect([[
+        1/chunk 1 (start)
+        1/chunk 2 (end)
+        2/chunk 1 (start)
+        2/chunk 2
+        2/chunk 3
+        2/chunk 4 (end)
+        ]])
+      feed('u')  -- Undo.
+      expect(expected1)
+    end)
     it('non-streaming', function()
       -- With final "\n".
       nvim('paste', 'line 1\nline 2\nline 3\n', true, -1)

test/functional/terminal/tui_spec.lua

@@ -505,7 +505,7 @@ describe('TUI', function()
                                                         |
       {4:~                                                 }|
       {5:                                                  }|
-      {8:paste: Error executing lua: vim.lua:194: Vim:E21: }|
+      {8:paste: Error executing lua: vim.lua:196: Vim:E21: }|
       {8:Cannot make changes, 'modifiable' is off}          |
       {10:Press ENTER or type command to continue}{1: }          |
       {3:-- TERMINAL --}                                    |