Evolution of shells in Linux (developerWorks)

I generally like this behaviour because it means you can go up or down in history (for reference) while editing a command line, without losing your edits in progress.

I guess you already know this, but as a workaround there's always alt+r, for 'undo all changes to this line'.

Also, there's alt+# for 'comment out this line and add it to my history', which is very useful when you've been editing a line in your history, decided you don't want to execute it now, don't want your history destructively edited, but might want to come back to it later.