patch 8.1.2017: cannot execute commands after closing the cmdline window

Problem:    Cannot execute commands after closing the cmdline window.
Solution:   Also trigger BufEnter and WinEnter. (closes #4762)

runtime/doc/autocmd.txt

@@ -554,16 +554,14 @@ CmdlineLeave			Before leaving the command line.
 							*CmdwinEnter*
 CmdwinEnter			After entering the command-line window.
 				Useful for setting options specifically for
-				this special type of window.  This is
+				this special type of window.
-				triggered _instead_ of BufEnter and WinEnter.
 				<afile> is set to a single character,
 				indicating the type of command-line.
 				|cmdwin-char|
 							*CmdwinLeave*
 CmdwinLeave			Before leaving the command-line window.
 				Useful to clean up any global setting done
-				with CmdwinEnter.  This is triggered _instead_
+				with CmdwinEnter.
-				of BufLeave and WinLeave.
 				<afile> is set to a single character,
 				indicating the type of command-line.
 				|cmdwin-char|

runtime/doc/cmdline.txt

@@ -1171,11 +1171,9 @@ edited as described in |cmdwin-char|.
 
 AUTOCOMMANDS
 
-Two autocommand events are used: |CmdwinEnter| and |CmdwinLeave|.  Since this
+Two autocommand events are used: |CmdwinEnter| and |CmdwinLeave|.  You can use
-window is of a special type, the WinEnter, WinLeave, BufEnter and BufLeave
+the Cmdwin events to do settings specifically for the command-line window.
-events are not triggered.  You can use the Cmdwin events to do settings
+Be careful not to cause side effects!
-specifically for the command-line window.  Be careful not to cause side
-effects!
 Example: >
 	:au CmdwinEnter :  let b:cpt_save = &cpt | set cpt=.
 	:au CmdwinLeave :  let &cpt = b:cpt_save

src/ex_getln.c

@@ -4069,30 +4069,26 @@ open_cmdwin(void)
     }
     set_bufref(&old_curbuf, curbuf);
 
-    /* Save current window sizes. */
+    // Save current window sizes.
     win_size_save(&winsizes);
 
-    /* Don't execute autocommands while creating the window. */
-    block_autocmds();
-
     // When using completion in Insert mode with <C-R>=<C-F> one can open the
     // command line window, but we don't want the popup menu then.
     pum_undisplay();
 
-    /* don't use a new tab page */
+    // don't use a new tab page
     cmdmod.tab = 0;
     cmdmod.noswapfile = 1;
 
-    /* Create a window for the command-line buffer. */
+    // Create a window for the command-line buffer.
     if (win_split((int)p_cwh, WSP_BOT) == FAIL)
     {
 	beep_flush();
-	unblock_autocmds();
 	return K_IGNORE;
     }
     cmdwin_type = get_cmdline_type();
 
-    /* Create the command-line buffer empty. */
+    // Create the command-line buffer empty.
     (void)do_ecmd(0, NULL, NULL, NULL, ECMD_ONE, ECMD_HIDE, NULL);
     (void)setfname(curbuf, (char_u *)"[Command Line]", NULL, TRUE);
     set_option_value((char_u *)"bt", 0L, (char_u *)"nofile", OPT_LOCAL);
@@ -4106,12 +4102,10 @@ open_cmdwin(void)
 # endif
     RESET_BINDING(curwin);
 
-    /* Do execute autocommands for setting the filetype (load syntax). */
+    // Don't allow switching to another buffer.
-    unblock_autocmds();
-    /* But don't allow switching to another buffer. */
     ++curbuf_lock;
 
-    /* Showing the prompt may have set need_wait_return, reset it. */
+    // Showing the prompt may have set need_wait_return, reset it.
     need_wait_return = FALSE;
 
     histtype = hist_char2type(cmdwin_type);
@@ -4126,11 +4120,11 @@ open_cmdwin(void)
     }
     --curbuf_lock;
 
-    /* Reset 'textwidth' after setting 'filetype' (the Vim filetype plugin
+    // Reset 'textwidth' after setting 'filetype' (the Vim filetype plugin
-     * sets 'textwidth' to 78). */
+    // sets 'textwidth' to 78).
     curbuf->b_p_tw = 0;
 
-    /* Fill the buffer with the history. */
+    // Fill the buffer with the history.
     init_history();
     if (get_hislen() > 0)
     {
@@ -4167,9 +4161,9 @@ open_cmdwin(void)
     setmouse();
 # endif
 
-    /* Trigger CmdwinEnter autocommands. */
+    // Trigger CmdwinEnter autocommands.
     trigger_cmd_autocmd(cmdwin_type, EVENT_CMDWINENTER);
-    if (restart_edit != 0)	/* autocmd with ":startinsert" */
+    if (restart_edit != 0)	// autocmd with ":startinsert"
 	stuffcharReadbuff(K_NOP);
 
     i = RedrawingDisabled;
@@ -4187,11 +4181,11 @@ open_cmdwin(void)
     save_KeyTyped = KeyTyped;
 # endif
 
-    /* Trigger CmdwinLeave autocommands. */
+    // Trigger CmdwinLeave autocommands.
     trigger_cmd_autocmd(cmdwin_type, EVENT_CMDWINLEAVE);
 
 # ifdef FEAT_FOLDING
-    /* Restore KeyTyped in case it is modified by autocommands */
+    // Restore KeyTyped in case it is modified by autocommands
     KeyTyped = save_KeyTyped;
 # endif
 
@@ -4268,10 +4262,8 @@ open_cmdwin(void)
 	    }
 	}
 
-	/* Don't execute autocommands while deleting the window. */
-	block_autocmds();
 # ifdef FEAT_CONCEAL
-	/* Avoid command-line window first character being concealed. */
+	// Avoid command-line window first character being concealed.
 	curwin->w_p_cole = 0;
 # endif
 	wp = curwin;
@@ -4279,15 +4271,13 @@ open_cmdwin(void)
 	win_goto(old_curwin);
 	win_close(wp, TRUE);
 
-	/* win_close() may have already wiped the buffer when 'bh' is
+	// win_close() may have already wiped the buffer when 'bh' is
-	 * set to 'wipe' */
+	// set to 'wipe'
 	if (bufref_valid(&bufref))
 	    close_buffer(NULL, bufref.br_buf, DOBUF_WIPE, FALSE);
 
-	/* Restore window sizes. */
+	// Restore window sizes.
 	win_size_restore(&winsizes);
-
-	unblock_autocmds();
     }
 
     ga_clear(&winsizes);
@@ -4303,7 +4293,7 @@ open_cmdwin(void)
 
     return cmdwin_result;
 }
-#endif /* FEAT_CMDWIN */
+#endif // FEAT_CMDWIN
 
 /*
  * Used for commands that either take a simple command string argument, or:

src/testdir/test_cmdline.vim

@@ -604,6 +604,8 @@ func Check_cmdline(cmdtype)
   return ''
 endfunc
 
+set cpo&
+
 func Test_getcmdtype()
   call feedkeys(":MyCmd a\<C-R>=Check_cmdline(':')\<CR>\<Esc>", "xt")
 
@@ -644,6 +646,37 @@ func Test_getcmdwintype()
   call assert_equal('', getcmdwintype())
 endfunc
 
+func Test_getcmdwin_autocmd()
+  let s:seq = []
+  augroup CmdWin
+  au WinEnter * call add(s:seq, 'WinEnter ' .. win_getid())
+  au WinLeave * call add(s:seq, 'WinLeave ' .. win_getid())
+  au BufEnter * call add(s:seq, 'BufEnter ' .. bufnr())
+  au BufLeave * call add(s:seq, 'BufLeave ' .. bufnr())
+  au CmdWinEnter * call add(s:seq, 'CmdWinEnter ' .. win_getid())
+  au CmdWinLeave * call add(s:seq, 'CmdWinLeave ' .. win_getid())
+
+  let org_winid = win_getid()
+  let org_bufnr = bufnr()
+  call feedkeys("q::let a = getcmdwintype()\<CR>:let s:cmd_winid = win_getid()\<CR>:let s:cmd_bufnr = bufnr()\<CR>:q\<CR>", 'x!')
+  call assert_equal(':', a)
+  call assert_equal([
+	\ 'WinLeave ' .. org_winid,
+	\ 'WinEnter ' .. s:cmd_winid,
+	\ 'BufLeave ' .. org_bufnr,
+	\ 'BufEnter ' .. s:cmd_bufnr,
+	\ 'CmdWinEnter ' .. s:cmd_winid,
+	\ 'CmdWinLeave ' .. s:cmd_winid,
+	\ 'BufLeave ' .. s:cmd_bufnr,
+	\ 'WinLeave ' .. s:cmd_winid,
+	\ 'WinEnter ' .. org_winid,
+	\ 'BufEnter ' .. org_bufnr,
+	\ ], s:seq)
+
+  au!
+  augroup END
+endfunc
+
 func Test_verbosefile()
   set verbosefile=Xlog
   echomsg 'foo'
@@ -701,5 +734,3 @@ func Test_cmdline_overstrike()
 
   let &encoding = encoding_save
 endfunc
-
-set cpo&

src/version.c

@@ -757,6 +757,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2017,
 /**/
     2016,
 /**/