patch 9.0.2032: cannot get mouse click pos for tab or virt text

Problem:  Cannot accurately get mouse clicking position when clicking on
          a TAB or with virtual text.
Solution: Add a "coladd" field to getmousepos() result.

closes: #13335

Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: zeertzjq <zeertzjq@outlook.com>
diff --git a/src/testdir/test_popupwin.vim b/src/testdir/test_popupwin.vim
index a256ddf..d01eccc 100644
--- a/src/testdir/test_popupwin.vim
+++ b/src/testdir/test_popupwin.vim
@@ -2671,21 +2671,21 @@
     eval a:tests->add(#{clickrow: a:row, clickcol: a:col, result: #{
 	  \ screenrow: a:row, screencol: a:col,
 	  \ winid: win_getid(), winrow: a:row, wincol: a:col,
-	  \ line: a:row, column: a:col,
+	  \ line: a:row, column: a:col, coladd: 0,
 	  \ }})
   endfunc
   func AddItemInPopupBorder(tests, winid, row, col)
     eval a:tests->add(#{clickrow: a:row, clickcol: a:col, result: #{
 	  \ screenrow: a:row, screencol: a:col,
 	  \ winid: a:winid, winrow: a:row - 1, wincol: a:col - 3,
-	  \ line: 0, column: 0,
+	  \ line: 0, column: 0, coladd: 0,
 	  \ }})
   endfunc
-  func AddItemInPopupText(tests, winid, row, col, textline, textcol)
+  func AddItemInPopupText(tests, winid, row, col, textline, textcol, coladd = 0)
     eval a:tests->add(#{clickrow: a:row, clickcol: a:col, result: #{
 	  \ screenrow: a:row, screencol: a:col,
 	  \ winid: a:winid, winrow: a:row - 1, wincol: a:col - 3,
-	  \ line: a:textline, column: a:textcol,
+	  \ line: a:textline, column: a:textcol, coladd: a:coladd,
 	  \ }})
   endfunc
 
@@ -2717,7 +2717,7 @@
   call AddItemInPopupText(tests, winid, 4, 6, 1, 1)
   call AddItemInPopupText(tests, winid, 4, 10, 1, 5)
   call AddItemInPopupText(tests, winid, 4, 11, 1, 6)
-  call AddItemInPopupText(tests, winid, 4, 17, 1, 6)
+  call AddItemInPopupText(tests, winid, 4, 17, 1, 6, 6)
   " text "long line th"
   call AddItemInPopupText(tests, winid, 5, 6, 2, 1)
   call AddItemInPopupText(tests, winid, 5, 10, 2, 5)
@@ -2730,7 +2730,7 @@
   call AddItemInPopupText(tests, winid, 7, 6, 3, 1)
   call AddItemInPopupText(tests, winid, 7, 10, 3, 5)
   call AddItemInPopupText(tests, winid, 7, 11, 3, 6)
-  call AddItemInPopupText(tests, winid, 7, 17, 3, 6)
+  call AddItemInPopupText(tests, winid, 7, 17, 3, 6, 6)
 
   for item in tests
     call test_setmouse(item.clickrow, item.clickcol)