patch 8.2.2830: terminal colors are not updated when 'background' is set

Problem:    Terminal colors are not updated when 'background' is set.
Solution:   Call term_update_colors() for all terminals. (Marcin Szamotulski,
            closes #8171, closes #8150)
diff --git a/src/terminal.c b/src/terminal.c
index ce9f64b..7fbff46 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -4590,9 +4590,9 @@
  * Called when 'wincolor' was set.
  */
     void
-term_update_colors(void)
+term_update_colors(term_T *term)
 {
-    term_T *term = curwin->w_buffer->b_term;
+    win_T *wp;
 
     if (term->tl_vterm == NULL)
 	return;
@@ -4602,7 +4602,21 @@
 	    &term->tl_default_color.fg,
 	    &term->tl_default_color.bg);
 
-    redraw_later(NOT_VALID);
+    FOR_ALL_WINDOWS(wp)
+	if (wp->w_buffer == term->tl_buffer)
+	    redraw_win_later(wp, NOT_VALID);
+}
+
+/*
+ * Called when 'background' was set.
+ */
+    void
+term_update_colors_all(void)
+{
+    term_T *tp;
+
+    FOR_ALL_TERMS(tp)
+	term_update_colors(tp);
 }
 
 /*
@@ -5939,7 +5953,7 @@
 
     l = rettv->vval.v_list;
     FOR_ALL_TERMS(tp)
-	if (tp != NULL && tp->tl_buffer != NULL)
+	if (tp->tl_buffer != NULL)
 	    if (list_append_number(l,
 				   (varnumber_T)tp->tl_buffer->b_fnum) == FAIL)
 		return;