patch 8.1.0035: not easy to switch between prompt buffer and other windows

Problem:    Not easy to switch between prompt buffer and other windows.
Solution:   Accept CTRL-W commands in Insert mode.  Start and stop Insert mode
            as one would expect.

src/edit.c

@@ -811,6 +811,14 @@ edit(
 	    do
 	    {
 		c = safe_vgetc();
+
+		if (stop_insert_mode)
+		{
+		    // Insert mode ended, possibly from a callback.
+		    count = 0;
+		    nomove = TRUE;
+		    goto doESCkey;
+		}
 	    } while (c == K_IGNORE || c == K_NOP);
 
 	/* Don't want K_CURSORHOLD for the second key, e.g., after CTRL-V. */
@@ -1165,6 +1173,18 @@ doESCkey:
 	    break;
 
 	case Ctrl_W:	/* delete word before the cursor */
+#ifdef FEAT_JOB_CHANNEL
+	    if (bt_prompt(curbuf) && (mod_mask & MOD_MASK_SHIFT) == 0)
+	    {
+		// In a prompt window CTRL-W is used for window commands.
+		// Use Shift-CTRL-W to delete a word.
+		stuffcharReadbuff(Ctrl_W);
+		restart_edit = 'i';
+		nomove = TRUE;
+		count = 0;
+		goto doESCkey;
+	    }
+#endif
 	    did_backspace = ins_bs(c, BACKSPACE_WORD, &inserted_space);
 	    auto_format(FALSE, TRUE);
 	    break;
@@ -1869,6 +1889,19 @@ init_prompt(int cmdchar_todo)
 	coladvance((colnr_T)MAXCOL);
 	changed_bytes(curbuf->b_ml.ml_line_count, 0);
     }
+
+    // Insert always starts after the prompt, allow editing text after it.
+    if (Insstart_orig.lnum != curwin->w_cursor.lnum
+				   || Insstart_orig.col != (int)STRLEN(prompt))
+    {
+	Insstart.lnum = curwin->w_cursor.lnum;
+	Insstart.col = STRLEN(prompt);
+	Insstart_orig = Insstart;
+	Insstart_textlen = Insstart.col;
+	Insstart_blank_vcol = MAXCOL;
+	arrow_used = FALSE;
+    }
+
     if (cmdchar_todo == 'A')
 	coladvance((colnr_T)MAXCOL);
     if (cmdchar_todo == 'I' || curwin->w_cursor.col <= (int)STRLEN(prompt))

src/ex_docmd.c

@@ -7341,7 +7341,8 @@ ex_close(exarg_T *eap)
 	{
 	    if (eap->addr_count == 0)
 		ex_win_close(eap->forceit, curwin, NULL);
-	    else {
+	    else
+	    {
 		FOR_ALL_WINDOWS(win)
 		{
 		    winnr++;

src/structs.h

@@ -2360,6 +2360,8 @@ struct file_buffer
     char_u	*b_prompt_text;	     // set by prompt_setprompt()
     char_u	*b_prompt_callback;  // set by prompt_setcallback()
     partial_T	*b_prompt_partial;   // set by prompt_setcallback()
+    int		b_prompt_insert;     // value for restart_edit when entering
+				     // a prompt buffer window.
 #endif
 #ifdef FEAT_MZSCHEME
     void	*b_mzscheme_ref; /* The MzScheme reference to this buffer */

src/version.c

@@ -761,6 +761,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    35,
 /**/
     34,
 /**/

src/window.c

@@ -2103,6 +2103,29 @@ win_equal_rec(
     }
 }
 
+#ifdef FEAT_JOB_CHANNEL
+    static void
+leaving_window(win_T *win)
+{
+    // When leaving a prompt window stop Insert mode and perhaps restart
+    // it when entering that window again.
+    win->w_buffer->b_prompt_insert = restart_edit;
+    restart_edit = NUL;
+
+    // When leaving the window (or closing the window) was done from a
+    // callback we need to break out of the Insert mode loop.
+    if (State & INSERT)
+	stop_insert_mode = TRUE;
+}
+
+    static void
+entering_window(win_T *win)
+{
+    // When entering the prompt window may restart Insert mode.
+    restart_edit = win->w_buffer->b_prompt_insert;
+}
+#endif
+
 /*
  * Close all windows for buffer "buf".
  */
@@ -2231,6 +2254,9 @@ close_last_window_tabpage(
 	    if (h != tabline_height())
 		shell_new_rows();
 	}
+#ifdef FEAT_JOB_CHANNEL
+	entering_window(curwin);
+#endif
 	/* Since goto_tabpage_tp above did not trigger *Enter autocommands, do
 	 * that now. */
 	apply_autocmds(EVENT_TABCLOSED, NULL, NULL, FALSE, curbuf);
@@ -2296,6 +2322,9 @@ win_close(win_T *win, int free_buf)
 
     if (win == curwin)
     {
+#ifdef FEAT_JOB_CHANNEL
+	leaving_window(curwin);
+#endif
 	/*
 	 * Guess which window is going to be the new current window.
 	 * This may change because of the autocommands (sigh).
@@ -3649,6 +3678,9 @@ win_new_tabpage(int after)
 	 * scrollbars.  Have to update them anyway. */
 	gui_may_update_scrollbars();
 #endif
+#ifdef FEAT_JOB_CHANNEL
+	entering_window(curwin);
+#endif
 
 	redraw_all_later(CLEAR);
 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
@@ -3822,6 +3854,9 @@ leave_tabpage(
 {
     tabpage_T	*tp = curtab;
 
+#ifdef FEAT_JOB_CHANNEL
+    leaving_window(curwin);
+#endif
     reset_VIsual_and_resel();	/* stop Visual mode */
     if (trigger_leave_autocmds)
     {
@@ -4318,6 +4353,11 @@ win_enter_ext(
     if (wp == curwin && !curwin_invalid)	/* nothing to do */
 	return;
 
+#ifdef FEAT_JOB_CHANNEL
+    if (!curwin_invalid)
+	leaving_window(curwin);
+#endif
+
     if (!curwin_invalid && trigger_leave_autocmds)
     {
 	/*
@@ -4389,6 +4429,9 @@ win_enter_ext(
 	shorten_fnames(TRUE);
     }
 
+#ifdef FEAT_JOB_CHANNEL
+    entering_window(curwin);
+#endif
     if (trigger_new_autocmds)
 	apply_autocmds(EVENT_WINNEW, NULL, NULL, FALSE, curbuf);
     if (trigger_enter_autocmds)