patch 8.2.0748: cannot get a list of all popups

Problem:    Cannot get a list of all popups.
Solution:   Add popup_list().  Use it in the test runner.
diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index 8086bd5..8259e99 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -2627,6 +2627,8 @@
 popup_getoptions({id})		Dict	get options of popup window {id}
 popup_getpos({id})		Dict	get position of popup window {id}
 popup_hide({id})		none	hide popup menu {id}
+popup_list()			List	get a list of window IDs of al popups
+popup_locate({row}, {col})	Number 	get window ID of popup at position
 popup_menu({what}, {options})	Number	create a popup window used as a menu
 popup_move({id}, {options})	none	set position of popup window {id}
 popup_notification({what}, {options})
diff --git a/runtime/doc/popup.txt b/runtime/doc/popup.txt
index d0bf2c4..5950c47 100644
--- a/runtime/doc/popup.txt
+++ b/runtime/doc/popup.txt
@@ -198,6 +198,7 @@
 	|popup_getoptions()|	get current options for a popup
 	|popup_getpos()|	get actual position and size of a popup
 	|popup_locate()|	find popup window at a screen position
+	|popup_list()|		get list of all popups
 
 
 DETAILS						*popup-function-details*
@@ -423,6 +424,10 @@
 		Can also be used as a |method|: >
 			GetPopup()->popup_hide()
 
+popup_list()						 *popup_list()*
+		Return a List with the |window-ID| of all existing popups.
+
+
 popup_locate({row}, {col})				 *popup_locate()*
 		Return the |window-ID| of the popup at screen position {row}
 		and {col}.  If there are multiple popups the one with the
diff --git a/src/evalfunc.c b/src/evalfunc.c
index c010116..c499890 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -715,6 +715,7 @@
     {"popup_getoptions", 1, 1, FEARG_1,	  ret_dict_any,	PROP_FUNC(f_popup_getoptions)},
     {"popup_getpos",	1, 1, FEARG_1,	  ret_dict_any,	PROP_FUNC(f_popup_getpos)},
     {"popup_hide",	1, 1, FEARG_1,	  ret_void,	PROP_FUNC(f_popup_hide)},
+    {"popup_list",	0, 0, 0,	  ret_list_number, PROP_FUNC(f_popup_list)},
     {"popup_locate",	2, 2, 0,	  ret_number,	PROP_FUNC(f_popup_locate)},
     {"popup_menu",	2, 2, FEARG_1,	  ret_number,	PROP_FUNC(f_popup_menu)},
     {"popup_move",	2, 2, FEARG_1,	  ret_void,	PROP_FUNC(f_popup_move)},
diff --git a/src/popupwin.c b/src/popupwin.c
index f1f9f60..a244c32 100644
--- a/src/popupwin.c
+++ b/src/popupwin.c
@@ -2720,6 +2720,25 @@
 	hash_unlock(&dict->dv_hashtab);
     }
 }
+
+/*
+ * popup_list()
+ */
+    void
+f_popup_list(typval_T *argvars UNUSED, typval_T *rettv)
+{
+    win_T	*wp;
+    tabpage_T	*tp;
+
+    if (rettv_list_alloc(rettv) != OK)
+	return;
+    FOR_ALL_POPUPWINS(wp)
+	list_append_number(rettv->vval.v_list, wp->w_id);
+    FOR_ALL_TABPAGES(tp)
+	FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
+	    list_append_number(rettv->vval.v_list, wp->w_id);
+}
+
 /*
  * popup_locate({row}, {col})
  */
diff --git a/src/proto/popupwin.pro b/src/proto/popupwin.pro
index 4fa3013..02cdce3 100644
--- a/src/proto/popupwin.pro
+++ b/src/proto/popupwin.pro
@@ -40,6 +40,7 @@
 void f_popup_move(typval_T *argvars, typval_T *rettv);
 void f_popup_setoptions(typval_T *argvars, typval_T *rettv);
 void f_popup_getpos(typval_T *argvars, typval_T *rettv);
+void f_popup_list(typval_T *argvars, typval_T *rettv);
 void f_popup_locate(typval_T *argvars, typval_T *rettv);
 void f_popup_getoptions(typval_T *argvars, typval_T *rettv);
 int error_if_term_popup_window(void);
diff --git a/src/testdir/runtest.vim b/src/testdir/runtest.vim
index b9d85f4..b1e0528 100644
--- a/src/testdir/runtest.vim
+++ b/src/testdir/runtest.vim
@@ -188,8 +188,9 @@
   au!
   au SwapExists * call HandleSwapExists()
 
-  " Close any stray popup windows.
+  " Check for and close any stray popup windows.
   if has('popupwin')
+    call assert_equal([], popup_list())
     call popup_clear(1)
   endif
 
diff --git a/src/testdir/test_popupwin.vim b/src/testdir/test_popupwin.vim
index 5eecb19..a664346 100644
--- a/src/testdir/test_popupwin.vim
+++ b/src/testdir/test_popupwin.vim
@@ -428,7 +428,7 @@
   call delete('XtestPopupNospace')
 endfunc
 
-func Test_popup_firstline()
+func Test_popup_firstline_dump()
   CheckScreendump
 
   let lines =<< trim END
@@ -449,7 +449,9 @@
   " clean up
   call StopVimInTerminal(buf)
   call delete('XtestPopupFirstline')
+endfunc
 
+func Test_popup_firstline()
   let winid = popup_create(['1111', '222222', '33333', '44444'], #{
 	\ maxheight: 2,
 	\ firstline: 3,
@@ -491,6 +493,7 @@
   call popup_setoptions(winid, #{line: 3})
   call assert_equal(0, popup_getoptions(winid).firstline)
   call assert_equal(10, popup_getpos(winid).firstline)
+  call popup_close(winid)
 
   " CTRL-D scrolls down half a page
   let winid = popup_create(['xxx']->repeat(50), #{
@@ -826,10 +829,13 @@
 endfunc
 
 func Test_popup_valid_arguments()
+  call assert_equal(0, len(popup_list()))
+
   " Zero value is like the property wasn't there
   let winid = popup_create("text", #{col: 0})
   let pos = popup_getpos(winid)
   call assert_inrange(&columns / 2 - 1, &columns / 2 + 1, pos.col)
+  call assert_equal([winid], popup_list())
   call popup_clear()
 
   " using cursor column has minimum value of 1
@@ -1619,12 +1625,14 @@
   let pos = popup_getpos(winid)
   call assert_equal(5, pos.width)
   call assert_equal(5, pos.height)
+  call popup_close(winid)
 
   let winid = popup_create([], #{border: []})
   redraw
   let pos = popup_getpos(winid)
   call assert_equal(3, pos.width)
   call assert_equal(3, pos.height)
+  call popup_close(winid)
 endfunc
 
 func Test_popup_never_behind()
@@ -3323,8 +3331,9 @@
   set signcolumn=yes
   call setline(1, repeat('=', &columns))
   normal! ggg$
-  call popup_atcursor(repeat('x', 500), #{moved: 'any', border: []})
+  let winid = popup_atcursor(repeat('x', 500), #{moved: 'any', border: []})
 
+  call popup_close(winid)
   bwipe!
   set signcolumn&
 endfunc
diff --git a/src/version.c b/src/version.c
index 15956bb..7881e32 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    748,
+/**/
     747,
 /**/
     746,