fix(ui): reposition window if border is different than "none" (#1859)

Co-authored-by: William Boman <[email protected]>

Author: pedrog14

lua/mason-core/ui/display.lua

@@ -170,13 +170,10 @@ M._render_node = render_node
 
 ---@alias WindowOpts { effects?: table<string, fun()>, winhighlight?: string[], border?: string|table }
 
----@param size integer | float
+---@param size number
 ---@param viewport integer
 local function calc_size(size, viewport)
-    if size <= 1 then
-        return math.ceil(size * viewport)
-    end
-    return math.min(size, viewport)
+    return size > 1 and math.min(size, viewport) or math.floor(size * viewport)
 end
 
 ---@param opts WindowOpts
@@ -188,6 +185,11 @@ local function create_popup_window_opts(opts, sizes_only)
     local width = calc_size(settings.current.ui.width, columns)
     local row = math.floor((lines - height) / 2)
     local col = math.floor((columns - width) / 2)
+    if opts.border ~= "none" then
+        row = math.max(row - 1, 0)
+        col = math.max(col - 1, 0)
+    end
+
     local popup_layout = {
         height = height,
         width = width,