patch 9.0.1019: 'smoothscroll' and virtual text above don't work together

Problem:    'smoothscroll' and virtual text above don't work together.
            (Yee Cheng Chin)
Solution:   Skip virtual text above when w_skipcol is non-zero.
            (closes #11665)
diff --git a/src/testdir/test_textprop.vim b/src/testdir/test_textprop.vim
index 6493aef..1bda87f 100644
--- a/src/testdir/test_textprop.vim
+++ b/src/testdir/test_textprop.vim
@@ -3113,6 +3113,34 @@
   call StopVimInTerminal(buf)
 endfunc
 
+func Test_prop_above_below_smoothscroll()
+  CheckRunVimInTerminal
+
+  let lines =<< trim END
+      vim9script
+      setline(1, range(1, 10)->mapnew((_, v) => '" line ' .. v))
+
+      set smoothscroll wrap
+      call prop_type_add('mytype', {highlight: 'DiffChange'})
+      call prop_add(3, 0, {text: "insert above", type: "mytype", text_align: 'above'})
+      call prop_add(5, 0, {text: "insert above 1", type: "mytype", text_align: 'above'})
+      call prop_add(5, 0, {text: "insert above 2", type: "mytype", text_align: 'above'})
+      call prop_add(7, 0, {text: "insert below", type: "mytype", text_align: 'below'})
+      call prop_add(9, 0, {text: "insert below 1", type: "mytype", text_align: 'below'})
+      call prop_add(9, 0, {text: "insert below 2", type: "mytype", text_align: 'below'})
+  END
+  call writefile(lines, 'XscriptPropsSmoothscroll', 'D')
+  let buf = RunVimInTerminal('-S XscriptPropsSmoothscroll', #{rows: 8, cols: 60})
+  call VerifyScreenDump(buf, 'Test_prop_above_below_smoothscroll_1', {})
+
+  for nr in range(2, 16)
+    call term_sendkeys(buf, "\<C-E>")
+    call VerifyScreenDump(buf, 'Test_prop_above_below_smoothscroll_' .. nr, {})
+  endfor
+
+  call StopVimInTerminal(buf)
+endfunc
+
 func Test_props_with_text_override()
   CheckRunVimInTerminal