feat(TextPutPost): add TextPutPost autocommand

Adds a new autocommand, TextPutPost. This autocommand fires when the
user puts text with p or P.

The motivating feature for this change was to implement a plugin that
"carries" Java imports between files. I.e. yanking from one java file
and pasting into another would automatically add the imports required.

2 files changed, 53 insertions, 0 deletions

diff --git a/src/nvim/auevents.lua b/src/nvim/auevents.lua
index a75ee3bbd5..fb0062e524 100644
--- a/src/nvim/auevents.lua
+++ b/src/nvim/auevents.lua
@@ -110,6 +110,7 @@ return {
     'TextChangedP',           -- text was modified in Insert mode(popup)
     'TextChangedT',           -- text was modified in Terminal mode
     'TextYankPost',           -- after a yank or delete was done (y, d, c)
+    'TextPutPost',            -- after a put was done (p, P)
     'UIEnter',                -- after UI attaches
     'UILeave',                -- after UI detaches
     'User',                   -- user defined autocommand
diff --git a/src/nvim/ops.c b/src/nvim/ops.c
index 435ca106ab..cb56cb7027 100644
--- a/src/nvim/ops.c
+++ b/src/nvim/ops.c
@@ -2910,6 +2910,56 @@ static void do_autocmd_textyankpost(oparg_T *oap, yankreg_T *reg)
   recursive = false;
 }
 
+/// Execute autocommands for TextPutPost.
+///
+/// @param oap Operator arguments.
+/// @param reg The yank register used.
+static void do_autocmd_textputpost(int regname, yankreg_T *reg)
+  FUNC_ATTR_NONNULL_ALL
+{
+  static bool recursive = false;
+  int len;
+
+  if (recursive || !has_event(EVENT_TEXTPUTPOST)) {
+    // No autocommand was defined, or we yanked from this autocommand.
+    return;
+  }
+
+  recursive = true;
+
+  save_v_event_T save_v_event;
+  // Set the v:event dictionary with information about the yank.
+  dict_T *dict = get_v_event(&save_v_event);
+
+  // The yanked text contents.
+  list_T *const list = tv_list_alloc((ptrdiff_t)reg->y_size);
+  for (size_t i = 0; i < reg->y_size; i++) {
+    tv_list_append_string(list, (const char *)reg->y_array[i], -1);
+  }
+  tv_list_set_lock(list, VAR_FIXED);
+  (void)tv_dict_add_list(dict, S_LEN("regcontents"), list);
+
+  // Register type.
+  char buf[NUMBUFLEN + 6];
+  format_reg_type(reg->y_type, reg->y_width, buf, ARRAY_SIZE(buf));
+  (void)tv_dict_add_str(dict, S_LEN("regtype"), buf);
+
+  // Name of requested register, or empty string for unnamed operation.
+  len = (*utf_char2len)(regname);
+  buf[len] = 0;
+  utf_char2bytes(regname, buf);
+  recursive = true;
+  (void)tv_dict_add_str(dict, S_LEN("regname"), buf);
+
+  tv_dict_set_keys_readonly(dict);
+  textlock++;
+  apply_autocmds(EVENT_TEXTPUTPOST, NULL, NULL, false, curbuf);
+  textlock--;
+  restore_v_event(dict, &save_v_event);
+
+  recursive = false;
+}
+
 /// Put contents of register "regname" into the text.
 /// Caller must check "regname" to be valid!
 ///
@@ -3693,6 +3743,8 @@ error:
   curwin->w_set_curswant = true;
 
 end:
+  do_autocmd_textputpost(regname, reg);
+
   if (cmdmod.cmod_flags & CMOD_LOCKMARKS) {
     curbuf->b_op_start = orig_start;
     curbuf->b_op_end = orig_end;