Bug 1495327 - Specially forged Text Pasted into the Address Bar Causes Firefox to Freeze. r=adw

Differential Revision: https://phabricator.services.mozilla.com/D8239

--HG--
extra : moz-landing-system : lando

toolkit/components/places/UnifiedComplete.js

@@ -508,7 +508,9 @@ function looksLikeUrl(str, ignoreAlphanumericHosts = false) {
   // Single word including special chars.
   return !REGEXP_SPACES.test(str) &&
          (["/", "@", ":", "["].some(c => str.includes(c)) ||
-          (ignoreAlphanumericHosts ? /(.*\..*){3,}/.test(str) : str.includes(".")));
+          (ignoreAlphanumericHosts ?
+            /^([\[\]A-Z0-9.:-]+[\.:]){3,}[\[\]A-Z0-9.:-]+$/i.test(str) :
+            str.includes(".")));
 }
 
 /**