patch 8.1.1589: popup window does not indicate scroll position
Problem: Popup window does not indicate scroll position.
Solution: Add a scrollbar.
diff --git a/src/testdir/dumps/Test_popupwin_firstline.dump b/src/testdir/dumps/Test_popupwin_firstline.dump
index 276f4e5..7efcf3e 100644
--- a/src/testdir/dumps/Test_popupwin_firstline.dump
+++ b/src/testdir/dumps/Test_popupwin_firstline.dump
@@ -1,10 +1,10 @@
>1+0&#ffffff0| @73
|2| @73
|3| @73
-|4| @33|3+0#0000001#ffd7ff255@4| +0#0000000#ffffff0@34
-|5| @33|4+0#0000001#ffd7ff255@1| @2| +0#0000000#ffffff0@34
-|6| @33|5+0#0000001#ffd7ff255| @3| +0#0000000#ffffff0@34
-|7| @33|6+0#0000001#ffd7ff255@4| +0#0000000#ffffff0@34
+|4| @33|3+0#0000001#ffd7ff255@4| +0#0000000#a8a8a8255| +0&#ffffff0@33
+|5| @33|4+0#0000001#ffd7ff255@1| @2| +0#0000000#0000001| +0&#ffffff0@33
+|6| @33|5+0#0000001#ffd7ff255| @3| +0#0000000#a8a8a8255| +0&#ffffff0@33
+|7| @33|6+0#0000001#ffd7ff255@4| +0#0000000#a8a8a8255| +0&#ffffff0@33
|8| @73
|9| @73
@57|1|,|1| @10|T|o|p|
diff --git a/src/testdir/dumps/Test_popupwin_scroll_1.dump b/src/testdir/dumps/Test_popupwin_scroll_1.dump
new file mode 100644
index 0000000..dd0e0b3
--- /dev/null
+++ b/src/testdir/dumps/Test_popupwin_scroll_1.dump
@@ -0,0 +1,10 @@
+>1+0&#ffffff0| @73
+|2| @73
+|3| @73
+|4| @31|o+0#0000001#ffd7ff255|n|e| @4| +0#0000000#0000001| +0&#ffffff0@32
+|5| @31|t+0#0000001#ffd7ff255|w|o| @4| +0#0000000#a8a8a8255| +0&#ffffff0@32
+|6| @31|t+0#0000001#ffd7ff255|h|r|e@1| @2| +0#0000000#a8a8a8255| +0&#ffffff0@32
+|7| @31|f+0#0000001#ffd7ff255|o|u|r| @3| +0#0000000#a8a8a8255| +0&#ffffff0@32
+|8| @73
+|9| @73
+@57|1|,|1| @10|T|o|p|
diff --git a/src/testdir/dumps/Test_popupwin_scroll_2.dump b/src/testdir/dumps/Test_popupwin_scroll_2.dump
new file mode 100644
index 0000000..21d33da
--- /dev/null
+++ b/src/testdir/dumps/Test_popupwin_scroll_2.dump
@@ -0,0 +1,10 @@
+>1+0&#ffffff0| @73
+|2| @73
+|3| @73
+|4| @31|t+0#0000001#ffd7ff255|w|o| @4| +0#0000000#a8a8a8255| +0&#ffffff0@32
+|5| @31|t+0#0000001#ffd7ff255|h|r|e@1| @2| +0#0000000#0000001| +0&#ffffff0@32
+|6| @31|f+0#0000001#ffd7ff255|o|u|r| @3| +0#0000000#a8a8a8255| +0&#ffffff0@32
+|7| @31|f+0#0000001#ffd7ff255|i|v|e| @3| +0#0000000#a8a8a8255| +0&#ffffff0@32
+|8| @73
+|9| @73
+|:|c|a|l@1| |p|o|p|u|p|_|s|e|t|o|p|t|i|o|n|s|(|w|i|n|i|d|,| |{|'|f|i|r|s|t|l|i|n|e|'|:| |2|}|)| @9|1|,|1| @10|T|o|p|
diff --git a/src/testdir/dumps/Test_popupwin_scroll_3.dump b/src/testdir/dumps/Test_popupwin_scroll_3.dump
new file mode 100644
index 0000000..656e058
--- /dev/null
+++ b/src/testdir/dumps/Test_popupwin_scroll_3.dump
@@ -0,0 +1,10 @@
+>1+0&#ffffff0| @73
+|2| @73
+|3| @73
+|4| @31|s+0#0000001#ffd7ff255|i|x| @4| +0#0000000#a8a8a8255| +0&#ffffff0@32
+|5| @31|s+0#0000001#ffd7ff255|e|v|e|n| @2| +0#0000000#a8a8a8255| +0&#ffffff0@32
+|6| @31|e+0#0000001#ffd7ff255|i|g|h|t| @2| +0#0000000#a8a8a8255| +0&#ffffff0@32
+|7| @31|n+0#0000001#ffd7ff255|i|n|e| @3| +0#0000000#0000001| +0&#ffffff0@32
+|8| @73
+|9| @73
+|:|c|a|l@1| |p|o|p|u|p|_|s|e|t|o|p|t|i|o|n|s|(|w|i|n|i|d|,| |{|'|f|i|r|s|t|l|i|n|e|'|:| |6|}|)| @9|1|,|1| @10|T|o|p|
diff --git a/src/testdir/dumps/Test_popupwin_scroll_4.dump b/src/testdir/dumps/Test_popupwin_scroll_4.dump
new file mode 100644
index 0000000..5f35a1f
--- /dev/null
+++ b/src/testdir/dumps/Test_popupwin_scroll_4.dump
@@ -0,0 +1,10 @@
+>1+0&#ffffff0| @73
+|2| @73
+|3| @73
+|4| @73
+|5| @31|n+0#0000001#ffd7ff255|i|n|e| @3| +0#0000000#0000001| +0&#ffffff0@32
+|6| @73
+|7| @73
+|8| @73
+|9| @73
+|:|c|a|l@1| |p|o|p|u|p|_|s|e|t|o|p|t|i|o|n|s|(|w|i|n|i|d|,| |{|'|f|i|r|s|t|l|i|n|e|'|:| |9|}|)| @9|1|,|1| @10|T|o|p|