Usually, in text fields on Windows, you can triple click to select a line (ie: in Firefox textarea, paragraphs, Word, notepad etc triple click selects the line from previous linebreak character/file start to next linebreak character/EOF).
Log window does not offer such function (instead, triple click with do a word-selection when double-click and then does a cursor position set when 3rd click occur).
It could be usefull to have such triple click to select a line (and then copy it). It is usefull for me when it comes to insert a line in testing database using "Data" tab (right click, insert row) then copy the query line and paste it in *.sql file opened in the IDE (NetBeans or sometimes notepad++).