Steps to Reproduce

1. load attached zul
2. open the combobox popup in a Grid

Current Result

the popup contains extra space in height.

Expected Result

the popup's height just fits its content.

Debug Info

• The combobox in a Listbox also has this bug. It doesn't have such issue when it's out of Listbox/Grid.

Root Cause

• Listbox/Grid css below increases the line height and make height calculation incorrectly.

  .z-column-content,.z-row-content,.z-group-content,.z-groupfoot-content,.z-footer-content {
      
      line-height: 24px;
      
  }
  

• it happens since 8.0.1, and 8.0.0 doesn't have such issue.
• Need to find a general way to avoid being affected by parent component's CSS to solve similar issues in the future.

Workaround

.z-comboitem{
	line-height: normal;
}