Merge pull request #25872 from gpanders/osc52

feat(clipboard): add OSC 52 clipboard support

runtime/doc/news.txt

@@ -208,6 +208,9 @@ The following new APIs and features were added.
 • The |TermResponse| autocommand event can be used with |v:termresponse| to
   read escape sequence responses from the terminal.
 
+• A clipboard provider which uses OSC 52 to copy the selection to the system
+  clipboard is now bundled by default. |clipboard-osc52|
+
 ==============================================================================
 CHANGED FEATURES                                                 *news-changed*
 

runtime/doc/provider.txt

@@ -253,7 +253,35 @@ For Windows WSL, try this g:clipboard definition:
                 \   },
                 \   'cache_enabled': 0,
                 \ }
+<
+							    *clipboard-osc52*
+Nvim bundles a clipboard provider that allows copying to the system clipboard
+using OSC 52. OSC 52 is an Operating System Command control sequence that
+writes the copied text to the terminal emulator. If the terminal emulator
+supports OSC 52 then it will write the copied text into the system clipboard.
 
+This is most useful when using Nvim remotely (e.g. via ssh) as Nvim does not
+have direct access to the system clipboard in that case.
+
+Because not all terminal emulators support OSC 52, this provider must be opted
+into explicitly by setting the following |g:clipboard| definition: >lua
+
+    vim.g.clipboard = {
+      name = 'OSC 52',
+      copy = {
+        ['+'] = require('vim.clipboard.osc52').copy,
+        ['*'] = require('vim.clipboard.osc52').copy,
+      },
+      paste = {
+        ['+'] = require('vim.clipboard.osc52').paste,
+        ['*'] = require('vim.clipboard.osc52').paste,
+      },
+    }
+<
+Note that not all terminal emulators support reading from the system clipboard
+(and even for those that do, users should be aware of the security
+implications), so using OSC 52 for pasting may not be possible.
+<
 ==============================================================================
 Paste							*provider-paste* *paste*
 

runtime/lua/vim/clipboard/osc52.lua

@@ -0,0 +1,38 @@
+local M = {}
+
+function M.copy(lines)
+  local s = table.concat(lines, '\n')
+  io.stdout:write(string.format('\x1b]52;;%s\x1b\\', vim.base64.encode(s)))
+end
+
+function M.paste()
+  local contents = nil
+  local id = vim.api.nvim_create_autocmd('TermResponse', {
+    callback = function(args)
+      local resp = args.data ---@type string
+      local encoded = resp:match('\x1b%]52;%w?;([A-Za-z0-9+/=]*)')
+      if encoded then
+        contents = vim.base64.decode(encoded)
+        return true
+      end
+    end,
+  })
+
+  io.stdout:write('\x1b]52;;?\x1b\\')
+
+  vim.wait(1000, function()
+    return contents ~= nil
+  end)
+
+  -- Delete the autocommand if it didn't already delete itself
+  pcall(vim.api.nvim_del_autocmd, id)
+
+  if contents then
+    return vim.split(contents, '\n')
+  end
+
+  vim.notify('Timed out waiting for a clipboard response from the terminal', vim.log.levels.WARN)
+  return 0
+end
+
+return M

src/nvim/tui/input.c

@@ -11,7 +11,6 @@
 #include "nvim/api/private/helpers.h"
 #include "nvim/ascii.h"
 #include "nvim/charset.h"
-#include "nvim/eval.h"
 #include "nvim/event/defs.h"
 #include "nvim/log.h"
 #include "nvim/macros.h"
@@ -31,6 +30,7 @@
 #include "nvim/event/rstream.h"
 #include "nvim/msgpack_rpc/channel.h"
 
+#define READ_STREAM_SIZE 0xfff
 #define KEY_BUFFER_SIZE 0xfff
 
 static const struct kitty_key_map_entry {
@@ -153,7 +153,9 @@ void tinput_init(TermInput *input, Loop *loop)
   termkey_set_canonflags(input->tk, curflags | TERMKEY_CANON_DELBS);
 
   // setup input handle
-  rstream_init_fd(loop, &input->read_stream, input->in_fd, 0xfff);
+  rstream_init_fd(loop, &input->read_stream, input->in_fd, READ_STREAM_SIZE);
+  termkey_set_buffer_size(input->tk, rbuffer_capacity(input->read_stream.buffer));
+
   // initialize a timer handle for handling ESC with libtermkey
   time_watcher_init(loop, &input->timer_handle, input);
 }
@@ -758,9 +760,9 @@ static void handle_raw_buffer(TermInput *input, bool force)
     RBUFFER_UNTIL_EMPTY(input->read_stream.buffer, ptr, len) {
       size_t consumed = termkey_push_bytes(input->tk, ptr, MIN(count, len));
       // termkey_push_bytes can return (size_t)-1, so it is possible that
-      // `consumed > input->read_stream.buffer->size`, but since tk_getkeys is
+      // `consumed > rbuffer_size(input->read_stream.buffer)`, but since tk_getkeys is
       // called soon, it shouldn't happen.
-      assert(consumed <= input->read_stream.buffer->size);
+      assert(consumed <= rbuffer_size(input->read_stream.buffer));
       rbuffer_consumed(input->read_stream.buffer, consumed);
       // Process the keys now: there is no guarantee `count` will
       // fit into libtermkey's input buffer.