Check entire selection to trigger `DocView:scroll_to_make_visible`

This is needed for example when a selection has both `line1` and `col1`
at 1, and the left arrow is pressed: `line2` and `col2` change, while
`line1` and `col1` don't, but we still want to scroll.

data/core/commands/doc.lua

@@ -279,8 +279,10 @@ local commands = {
   ["doc:select-all"] = function()
     doc():set_selection(1, 1, math.huge, math.huge)
     -- avoid triggering DocView:scroll_to_make_visible
-    dv().last_line = 1
-    dv().last_col = 1
+    dv().last_line1 = 1
+    dv().last_col1 = 1
+    dv().last_line2 = #doc().lines
+    dv().last_col2 = #doc().lines[#doc().lines]
   end,
 
   ["doc:select-lines"] = function()

data/core/docview.lua

@@ -284,13 +284,15 @@ end
 
 function DocView:update()
   -- scroll to make caret visible and reset blink timer if it moved
-  local line, col = self.doc:get_selection()
-  if (line ~= self.last_line or col ~= self.last_col) and self.size.x > 0 then
+  local line1, col1, line2, col2 = self.doc:get_selection()
+  if (line1 ~= self.last_line1 or col1 ~= self.last_col1 or
+      line2 ~= self.last_line2 or col2 ~= self.last_col2) and self.size.x > 0 then
     if core.active_view == self then
-      self:scroll_to_make_visible(line, col)
+      self:scroll_to_make_visible(line1, col1)
     end
     core.blink_reset()
-    self.last_line, self.last_col = line, col
+    self.last_line1, self.last_col1 = line1, col1
+    self.last_line2, self.last_col2 = line2, col2
   end
 
   -- update blink timer