There are more cases in the codebase where empty text is set:

templates/repo/home_sidebar_top.tmpl:38:									<div class="text"></div>
templates/repo/issue/sidebar/issue_management.tmpl:59:							<div class="text"></div> {{svg "octicon-triangle-down" 14 "dropdown icon"}}
templates/shared/search/combo.tmpl:13:		<div class="text"></div> {{svg "octicon-triangle-down" 14 "dropdown icon"}}
templates/user/settings/notifications.tmpl:16:								<div class="text"></div>
templates/user/settings/notifications.tmpl:47:								<div class="text"></div>
web_src/fomantic/build/components/dropdown.js:4163:      html += '<div class="text"></div>';
web_src/js/modules/fomantic/aria.md:111:  <div class="text"></div>

I wonder if a CSS-based solution is possible which would fix all of them, not just this search box. Adding min-height: 16px does work but it may not be accurate depending on font.

Changed to min-height. Font size is 13px, I don't expect this to take up more than 16px even with other fonts. Currently the 13px renders as 15.8333px:

I don't think the patch is ideal.

Such hacky patches will just cause more problems: for example: it breaks the "small dropdown" layout.

Ultimately the issue stems from the fact that dropdown height is determined based on the text, and text height is variable with font size and whether text is present or not.

I think we may be able to find a better solution that sizes height independent on text, but it will likely limit dropdown text to single-line content (which I think is no issue).

I guess a devtest page is needed to render dropdowns of various sizes to ensure they all render correctly. I guess with a proper min-height on the root element, something clean might be possible.