Firefox did change default search engine to yahoo at some point, IIRC it was around the time yahoo was trying to sell itself at the best possible price. I reme

Firefox did change default search engine to yahoo at some point, IIRC it was around the time yahoo was trying to sell itself at the best possible price. I remember having to go through a dozen clients to fix their custom settings for search engines that had been switched to yahoo and eventually migrating some of them from firefox to waterfox.