tui: Add support bracketed paste

Inspired by the vim-bracketed-paste plugin but adapted for the new TUI. Also
initialize some variables of type `Error` that were uninitialized

2 files changed, 69 insertions, 10 deletions

diff --git a/src/nvim/tui/term_input.inl b/src/nvim/tui/term_input.inl
index 0c0e6c07c9..dba970e8f2 100644
--- a/src/nvim/tui/term_input.inl
+++ b/src/nvim/tui/term_input.inl
@@ -1,10 +1,12 @@
 #include <termkey.h>
 
 #include "nvim/ascii.h"
+#include "nvim/misc2.h"
 #include "nvim/os/os.h"
 #include "nvim/os/input.h"
 #include "nvim/os/rstream.h"
 
+#define PASTETOGGLE_KEY "<f37>"
 
 struct term_input {
   int in_fd;
@@ -113,7 +115,7 @@ static int get_key_code_timeout(void)
   bool timeout = false;
   // Check 'timeout' and 'ttimeout' to determine if we should send ESC
   // after 'ttimeoutlen'. See :help 'ttimeout' for more information
-  Error err;
+  Error err = ERROR_INIT;
   timeout = vim_get_option(cstr_as_string("timeout"), &err).data.boolean;
   if (!timeout) {
     timeout = vim_get_option(cstr_as_string("ttimeout"), &err).data.boolean;
@@ -164,6 +166,49 @@ static void timer_cb(uv_timer_t *handle)
   tk_getkeys(handle->data, true);
 }
 
+static bool handle_bracketed_paste(TermInput *input)
+{
+  char *ptr = rbuffer_read_ptr(input->read_buffer);
+  size_t len = rbuffer_pending(input->read_buffer);
+  if (len > 5 && (!strncmp(ptr, "\x1b[200~", 6)
+        || !strncmp(ptr, "\x1b[201~", 6))) {
+    bool enable = ptr[4] == '0';
+    // Advance past the sequence
+    rbuffer_consumed(input->read_buffer, 6);
+    if (enable) {
+      // Get the current mode
+      int state = get_real_state();
+      if (state & NORMAL) {
+        // Enter insert mode
+        input_enqueue(cstr_as_string("i"));
+      } else if (state & VISUAL) {
+        // Remove the selected text and enter insert mode
+        input_enqueue(cstr_as_string("c"));
+      } else if (!(state & INSERT)) {
+        // Don't mess with the paste option
+        return true;
+      }
+    }
+    input_enqueue(cstr_as_string(PASTETOGGLE_KEY));
+    return true;
+  }
+  return false;
+}
+
+static bool handle_forced_escape(TermInput *input)
+{
+  char *ptr = rbuffer_read_ptr(input->read_buffer);
+  size_t len = rbuffer_pending(input->read_buffer);
+  if (len > 1 && ptr[0] == ESC && ptr[1] == NUL) {
+    // skip the ESC and NUL and push one <esc> to the input buffer
+    termkey_push_bytes(input->tk, ptr, 1);
+    rbuffer_consumed(input->read_buffer, 2);
+    tk_getkeys(input, true);
+    return true;
+  }
+  return false;
+}
+
 static void read_cb(RStream *rstream, void *rstream_data, bool eof)
 {
   if (eof) {
@@ -174,15 +219,11 @@ static void read_cb(RStream *rstream, void *rstream_data, bool eof)
   TermInput *input = rstream_data;
 
   do {
-    char *ptr = rbuffer_read_ptr(input->read_buffer);
-    size_t len = rbuffer_pending(input->read_buffer);
-    if (len > 1 && ptr[0] == ESC && ptr[1] == NUL) {
-      // skip the ESC and NUL and push one <esc> to the input buffer
-      termkey_push_bytes(input->tk, ptr, 1);
-      rbuffer_consumed(input->read_buffer, 2);
-      tk_getkeys(input, true);
+    if (handle_bracketed_paste(input) || handle_forced_escape(input)) {
       continue;
     }
+    char *ptr = rbuffer_read_ptr(input->read_buffer);
+    size_t len = rbuffer_pending(input->read_buffer);
     // Find the next 'esc' and push everything up to it(excluding)
     size_t i;
     for (i = ptr[0] == ESC ? 1 : 0; i < len; i++) {
@@ -228,6 +269,11 @@ static TermInput *term_input_new(void)
   // initialize a timer handle for handling ESC with libtermkey
   uv_timer_init(uv_default_loop(), &rv->timer_handle);
   rv->timer_handle.data = rv;
+  // Set the pastetoggle option to a special key that will be sent when
+  // \e[20{0,1}~/ are received
+  Error err = ERROR_INIT;
+  vim_set_option(cstr_as_string("pastetoggle"),
+      STRING_OBJ(cstr_as_string(PASTETOGGLE_KEY)), &err);
   return rv;
 }
 
diff --git a/src/nvim/tui/tui.c b/src/nvim/tui/tui.c
index 575a75adec..44296cf446 100644
--- a/src/nvim/tui/tui.c
+++ b/src/nvim/tui/tui.c
@@ -50,6 +50,7 @@ typedef struct {
   Cell **screen;
   struct {
     size_t enable_mouse, disable_mouse;
+    size_t enable_bracketed_paste, disable_bracketed_paste;
   } unibi_ext;
 } TUIData;
 
@@ -103,6 +104,8 @@ void tui_start(void)
   // Enter alternate screen and clear
   unibi_out(ui, unibi_enter_ca_mode, NULL);
   unibi_out(ui, unibi_clear_screen, NULL);
+  // Enable bracketed paste
+  unibi_out(ui, (int)data->unibi_ext.enable_bracketed_paste, NULL);
 
   // setup output handle in a separate event loop(we wanna do synchronous
   // write to the tty)
@@ -162,6 +165,8 @@ static void tui_stop(UI *ui)
   unibi_out(ui, unibi_exit_attribute_mode, NULL);
   unibi_out(ui, unibi_cursor_normal, NULL);
   unibi_out(ui, unibi_exit_ca_mode, NULL);
+  // Disable bracketed paste
+  unibi_out(ui, (int)data->unibi_ext.disable_bracketed_paste, NULL);
   flush_buf(ui);
   uv_close((uv_handle_t *)&data->output_handle, NULL);
   uv_run(data->write_loop, UV_RUN_DEFAULT);
@@ -665,6 +670,8 @@ static void fix_terminfo(TUIData *data)
     goto end;
   }
 
+  bool inside_tmux = os_getenv("TMUX") != NULL;
+
 #define STARTS_WITH(str, prefix) (!memcmp(str, prefix, sizeof(prefix) - 1))
 
   if (STARTS_WITH(term, "rxvt")) {
@@ -689,13 +696,19 @@ static void fix_terminfo(TUIData *data)
     unibi_set_if_empty(ut, unibi_from_status_line, "\x07");
   }
 
+  if (STARTS_WITH(term, "xterm") || STARTS_WITH(term, "rxvt") || inside_tmux) {
+    data->unibi_ext.enable_bracketed_paste = unibi_add_ext_str(ut, NULL,
+        "\x1b[?2004h");
+    data->unibi_ext.disable_bracketed_paste = unibi_add_ext_str(ut, NULL,
+        "\x1b[?2004l");
+  }
+
 end:
   // Fill some empty slots with common terminal strings
   data->unibi_ext.enable_mouse = unibi_add_ext_str(ut, NULL,
       "\x1b[?1002h\x1b[?1006h");
   data->unibi_ext.disable_mouse = unibi_add_ext_str(ut, NULL,
       "\x1b[?1002l\x1b[?1006l");
-
   unibi_set_if_empty(ut, unibi_cursor_address, "\x1b[%i%p1%d;%p2%dH");
   unibi_set_if_empty(ut, unibi_exit_attribute_mode, "\x1b[0;10m");
   unibi_set_if_empty(ut, unibi_set_a_foreground,
@@ -735,7 +748,7 @@ static char *get_term_option(UI *ui, char *option)
 
   char *rv = pmap_get(cstr_t)(data->option_cache, option);
   if (!rv) {
-    Error err;
+    Error err = ERROR_INIT;
     Object val = vim_get_option(cstr_as_string(option), &err);
     if (val.type == kObjectTypeString) {
       rv = val.data.string.data;