patch 8.1.1407: popup_create() does not support text properties

Problem:    Popup_create() does not support text properties.
Solution:   Support the third form of the text argument.
diff --git a/src/screen.c b/src/screen.c
index 40cff9a..7354220 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -4405,7 +4405,10 @@
 		char_attr = hl_combine_attr(line_attr, search_attr);
 # ifdef FEAT_TEXT_PROP
 	    else if (text_prop_type != NULL)
-		char_attr = hl_combine_attr(line_attr, text_prop_attr);
+	    {
+		char_attr = hl_combine_attr(
+			line_attr != 0 ? line_attr : win_attr, text_prop_attr);
+	    }
 # endif
 	    else if (line_attr != 0 && ((fromcol == -10 && tocol == MAXCOL)
 				|| vcol < fromcol || vcol_prev < fromcol_prev
@@ -4429,7 +4432,8 @@
 			char_attr = hl_combine_attr(
 						  syntax_attr, text_prop_attr);
 		    else
-			char_attr = text_prop_attr;
+			char_attr = hl_combine_attr(
+						  win_attr, text_prop_attr);
 		}
 		else
 #endif