patch 8.2.1414: popupwindow missing last couple of lines

Problem:    Popupwindow missing last couple of lines when cursor is in the
            first line.
Solution:   Compute the max height also when top aligned. (closes #6664)
diff --git a/src/testdir/dumps/Test_popupwin_nospace.dump b/src/testdir/dumps/Test_popupwin_nospace.dump
index 9eaacf0..de8521c 100644
--- a/src/testdir/dumps/Test_popupwin_nospace.dump
+++ b/src/testdir/dumps/Test_popupwin_nospace.dump
@@ -3,10 +3,10 @@
 |-|║+0#0000001#ffd7ff255|t|w|o|║|-+0#0000000#ffffff0@1|║+0#0000001#ffd7ff255|t|w|o|║|-+0#0000000#ffffff0@8|║+0#0000001#ffd7ff255|b@2|║|-+0#0000000#ffffff0@15|║+0#0000001#ffd7ff255|t|w|o|║|-+0#0000000#ffffff0@11| @14
 |-|╚+0#0000001#ffd7ff255|═@2|╝|-+0#0000000#ffffff0@1|╚+0#0000001#ffd7ff255|═@2|╝|-+0#0000000#ffffff0@8|║+0#0000001#ffd7ff255|c@2|║|-+0#0000000#ffffff0@15|║+0#0000001#ffd7ff255|t|e@1|║|-+0#0000000#ffffff0@11| @14
 |-|@|-@5|#|-@5|%|-@5|║+0#0000001#ffd7ff255|d@2|║|-+0#0000000#ffffff0@15|║+0#0000001#ffd7ff255|f|o|u|║|-+0#0000000#ffffff0@1>*|-@8| @14
-|-@14|╔+0#0000001#ffd7ff255|═@2|╗|-+0#0000000#ffffff0@1|║+0#0000001#ffd7ff255|e@2|║|-+0#0000000#ffffff0@15|║+0#0000001#ffd7ff255|f|i|v|║|-+0#0000000#ffffff0@1|╔+0#0000001#ffd7ff255|═@2|╗|-+0#0000000#ffffff0@4| @14
-|-@14|║+0#0000001#ffd7ff255|o|n|e|║|-+0#0000000#ffffff0@1|╚+0#0000001#ffd7ff255|═@2|╝|-+0#0000000#ffffff0@15|╚+0#0000001#ffd7ff255|═@2|╝|-+0#0000000#ffffff0@1|║+0#0000001#ffd7ff255|a@2|║|-+0#0000000#ffffff0@4| @14
-|-@14|║+0#0000001#ffd7ff255|t|w|o|║|-+0#0000000#ffffff0@1|*|-@5|@|-@5|#|-@5|%|-@5|║+0#0000001#ffd7ff255|b@2|║|-+0#0000000#ffffff0@4| @14
-|-@14|║+0#0000001#ffd7ff255|t|e@1|║|-+0#0000000#ffffff0@8|╔+0#0000001#ffd7ff255|═@2|╗|-+0#0000000#ffffff0@1|╔+0#0000001#ffd7ff255|═@2|╗|-+0#0000000#ffffff0@8|║+0#0000001#ffd7ff255|c@2|║|-+0#0000000#ffffff0@4| @14
-|-@14|╚+0#0000001#ffd7ff255|═@2|╝|-+0#0000000#ffffff0@8|║+0#0000001#ffd7ff255|o|n|e|║|-+0#0000000#ffffff0@1|║+0#0000001#ffd7ff255|o|n|e|║|-+0#0000000#ffffff0@8|║+0#0000001#ffd7ff255|d@2|║|-+0#0000000#ffffff0@4| @14
-|-@28|║+0#0000001#ffd7ff255|t|w|o|║|-+0#0000000#ffffff0@1|║+0#0000001#ffd7ff255|t|w|o|║|-+0#0000000#ffffff0@8|║+0#0000001#ffd7ff255|e@2|║|-+0#0000000#ffffff0@4| @14
-@29|╚+0#0000001#ffd7ff255|═@2|╝| +0#0000000#ffffff0@1|║+0#0000001#ffd7ff255|t|e@1|║| +0#0000000#ffffff0@8|║+0#0000001#ffd7ff255|f@2|║| +0#0000000#ffffff0@1|5|,|5|1| @9|T|o|p| 
+|-@14|╔+0#0000001#ffd7ff255|═@2|╗|-+0#0000000#ffffff0@1|║+0#0000001#ffd7ff255|e@2|║|-+0#0000000#ffffff0@15|║+0#0000001#ffd7ff255|f|i|v|║|-+0#0000000#ffffff0@1|╔+0#0000001#ffd7ff255|═@3|╗|-+0#0000000#ffffff0@3| @14
+|-@14|║+0#0000001#ffd7ff255|o|n|e|║|-+0#0000000#ffffff0@1|╚+0#0000001#ffd7ff255|═@2|╝|-+0#0000000#ffffff0@15|╚+0#0000001#ffd7ff255|═@2|╝|-+0#0000000#ffffff0@1|║+0#0000001#ffd7ff255|a@2| +0#0000000#0000001|║+0#0000001#ffd7ff255|-+0#0000000#ffffff0@3| @14
+|-@14|║+0#0000001#ffd7ff255|t|w|o|║|-+0#0000000#ffffff0@1|*|-@5|@|-@5|#|-@5|%|-@5|║+0#0000001#ffd7ff255|b@2| +0#0000000#0000001|║+0#0000001#ffd7ff255|-+0#0000000#ffffff0@3| @14
+|-@14|║+0#0000001#ffd7ff255|t|e@1|║|-+0#0000000#ffffff0@8|╔+0#0000001#ffd7ff255|═@2|╗|-+0#0000000#ffffff0@1|╔+0#0000001#ffd7ff255|═@3|╗|-+0#0000000#ffffff0@7|║+0#0000001#ffd7ff255|c@2| +0#0000000#0000001|║+0#0000001#ffd7ff255|-+0#0000000#ffffff0@3| @14
+|-@14|╚+0#0000001#ffd7ff255|═@2|╝|-+0#0000000#ffffff0@8|║+0#0000001#ffd7ff255|o|n|e|║|-+0#0000000#ffffff0@1|║+0#0000001#ffd7ff255|o|n|e| +0#0000000#0000001|║+0#0000001#ffd7ff255|-+0#0000000#ffffff0@7|║+0#0000001#ffd7ff255|d@2| +0#0000000#0000001|║+0#0000001#ffd7ff255|-+0#0000000#ffffff0@3| @14
+|-@28|║+0#0000001#ffd7ff255|t|w|o|║|-+0#0000000#ffffff0@1|║+0#0000001#ffd7ff255|t|w|o| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255|-+0#0000000#ffffff0@7|║+0#0000001#ffd7ff255|e@2| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255|-+0#0000000#ffffff0@3| @14
+@29|╚+0#0000001#ffd7ff255|═@2|╝| +0#0000000#ffffff0@1|╚+0#0000001#ffd7ff255|═@3|╝| +0#0000000#ffffff0@7|╚+0#0000001#ffd7ff255|═@3|╝| +0#0000000#ffffff0|5|,|5|1| @9|T|o|p| 
diff --git a/src/testdir/dumps/Test_popupwin_toohigh_3.dump b/src/testdir/dumps/Test_popupwin_toohigh_3.dump
new file mode 100644
index 0000000..8c15a40
--- /dev/null
+++ b/src/testdir/dumps/Test_popupwin_toohigh_3.dump
@@ -0,0 +1,10 @@
+|1+0&#ffffff0@8>1| @64
+|2@8|╔+0#0000001#ffd7ff255|═@8|╗| +0#0000000#ffffff0@54
+|3@8|║+0#0000001#ffd7ff255|o|n|e| @4| +0#0000000#0000001|║+0#0000001#ffd7ff255| +0#0000000#ffffff0@54
+|4@8|║+0#0000001#ffd7ff255|t|w|o| @4| +0#0000000#0000001|║+0#0000001#ffd7ff255| +0#0000000#ffffff0@54
+|5@8|║+0#0000001#ffd7ff255|t|h|r|e@1| @2| +0#0000000#0000001|║+0#0000001#ffd7ff255| +0#0000000#ffffff0@54
+|6@8|║+0#0000001#ffd7ff255|f|o|u|r| @3| +0#0000000#0000001|║+0#0000001#ffd7ff255| +0#0000000#ffffff0@54
+|7@8|║+0#0000001#ffd7ff255|f|i|v|e| @3| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255| +0#0000000#ffffff0@54
+|8@8|║+0#0000001#ffd7ff255|s|i|x| @4| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255| +0#0000000#ffffff0@54
+|9@8|║+0#0000001#ffd7ff255|s|e|v|e|n| @2| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255| +0#0000000#ffffff0@54
+|:|c|a|l@1| |S|h|o|╚+0#0000001#ffd7ff255|═@8|╝| +0#0000000#ffffff0@36|1|,|1|0| @9|T|o|p| 
diff --git a/src/testdir/test_popupwin.vim b/src/testdir/test_popupwin.vim
index c44c847..f13a7e0 100644
--- a/src/testdir/test_popupwin.vim
+++ b/src/testdir/test_popupwin.vim
@@ -753,6 +753,7 @@
 	    \ posinvert: 0,
 	    \ wrap: 0,
 	    \ fixed: 1,
+	    \ scrollbar: v:false,
 	    \ zindex: 90,
 	    \ padding: [],
 	    \ highlight: 'PopupColor',
@@ -772,6 +773,7 @@
 	    \ posinvert: 0,
 	    \ wrap: 0,
 	    \ fixed: 1,
+	    \ scrollbar: v:false,
 	    \ close: 'button',
 	    \ zindex: 90,
 	    \ padding: [],
@@ -2169,6 +2171,11 @@
   call term_sendkeys(buf, ":call ShowPopup()\<CR>")
   call VerifyScreenDump(buf, 'Test_popupwin_toohigh_2', {})
 
+  call term_sendkeys(buf, ":call popup_clear()\<CR>")
+  call term_sendkeys(buf, "gg$")
+  call term_sendkeys(buf, ":call ShowPopup()\<CR>")
+  call VerifyScreenDump(buf, 'Test_popupwin_toohigh_3', {})
+
   " clean up
   call StopVimInTerminal(buf)
   call delete('XtestPopupToohigh')