feat: ignore nore on <Plug> maps

runtime/doc/map.txt

@@ -65,6 +65,9 @@ modes.
 			where the map command applies.  Disallow mapping of
 			{rhs}, to avoid nested and recursive mappings.  Often
 			used to redefine a command.
+			Note: "nore" is ignored for a mapping whose result
+			starts with <Plug>.  <Plug> is always remapped even if
+			"nore" is used.
 
 
 :unm[ap]  {lhs}			|mapmode-nvo|		*:unm*  *:unmap*

runtime/doc/vim_diff.txt

@@ -442,6 +442,9 @@ Working directory (Vim implemented some of these later than Nvim):
 - `getcwd(-1)` is equivalent to `getcwd(-1, 0)` instead of returning the global
   working directory. Use `getcwd(-1, -1)` to get the global working directory.
 
+Mappings:
+- |nore| is ignored for rhs <Plug> mappings. <Plug> mappings are always remapped.
+
 ==============================================================================
 5. Missing legacy features				 *nvim-features-missing*
 

src/nvim/getchar.c

@@ -1710,6 +1710,15 @@ static int handle_mapping(int *keylenp, bool *timedout, int *mapdepth)
   int keylen = *keylenp;
   int i;
   int local_State = get_real_state();
+  bool is_plug_map = false;
+
+  // Check if typehead starts with a <Plug> mapping.
+  // In that case we will ignore nore flag on it.
+  if (typebuf.tb_buf[typebuf.tb_off] == K_SPECIAL
+      && typebuf.tb_buf[typebuf.tb_off+1] == KS_EXTRA
+      && typebuf.tb_buf[typebuf.tb_off+2] == KE_PLUG) {
+    is_plug_map = true;
+  }
 
   // Check for a mappable key sequence.
   // Walk through one maphash[] list until we find an entry that matches.
@@ -1725,7 +1734,7 @@ static int handle_mapping(int *keylenp, bool *timedout, int *mapdepth)
   tb_c1 = typebuf.tb_buf[typebuf.tb_off];
   if (no_mapping == 0 && maphash_valid
       && (no_zero_mapping == 0 || tb_c1 != '0')
-      && (typebuf.tb_maplen == 0
+      && (typebuf.tb_maplen == 0 || is_plug_map
           || (p_remap
               && !(typebuf.tb_noremap[typebuf.tb_off] & (RM_NONE|RM_ABBR))))
       && !(p_paste && (State & (INSERT + CMDLINE)))
@@ -1813,7 +1822,7 @@ static int handle_mapping(int *keylenp, bool *timedout, int *mapdepth)
               break;
             }
           }
-          if (n >= 0) {
+          if (!is_plug_map && n >= 0) {
             continue;
           }
 

test/functional/ex_cmds/map_spec.lua

@@ -6,6 +6,8 @@ local meths = helpers.meths
 local clear = helpers.clear
 local command = helpers.command
 local expect = helpers.expect
+local insert = helpers.insert
+local eval = helpers.eval
 
 describe(':*map', function()
   before_each(clear)
@@ -25,4 +27,37 @@ describe(':*map', function()
     feed('i-<M-">-')
     expect('-foo-')
   end)
+
+  it('<Plug> keymaps ignore nore', function()
+    command('let x = 0')
+    eq(0, meths.eval('x'))
+    command [[
+      nnoremap <Plug>(Increase_x) <cmd>let x+=1<cr>
+      nmap increase_x_remap <Plug>(Increase_x)
+      nnoremap increase_x_noremap <Plug>(Increase_x)
+    ]]
+    feed('increase_x_remap')
+    eq(1, meths.eval('x'))
+    feed('increase_x_noremap')
+    eq(2, meths.eval('x'))
+  end)
+  it("Doesn't auto ignore nore for keys before or after <Plug> keymap", function()
+    command('let x = 0')
+    eq(0, meths.eval('x'))
+    command [[
+      nnoremap x <nop>
+      nnoremap <Plug>(Increase_x) <cmd>let x+=1<cr>
+      nmap increase_x_remap x<Plug>(Increase_x)x
+      nnoremap increase_x_noremap x<Plug>(Increase_x)x
+    ]]
+    insert("Some text")
+    eq('Some text', eval("getline('.')"))
+
+    feed('increase_x_remap')
+    eq(1, meths.eval('x'))
+    eq('Some text', eval("getline('.')"))
+    feed('increase_x_noremap')
+    eq(2, meths.eval('x'))
+    eq('Some te', eval("getline('.')"))
+  end)
 end)