[OS X TeX] "Replace All" button in TeXShop

[Jung-Tsung Shen]

Just now I was trying to find a string in my manuscript. Instead of
the button "Find All", I accidentally pressed the button "Replace All"
and thus all the strings were deleted from my manuscript (since the
other field was empty) -- TeXShop effectively replaced the string by
empty space. I could undo it so that did not cause serious problem. I
am not sure how many back steps I could undo within TeXShop.

Is there a better way to avoid this? For example, if the second field
is empty then the "Replace All" would not work, unless you explicitly
specify a string such as ``empty'' [with some identifying characters].
I understand this proposed fix might cause more problems than the one
it is intended to solve. Any other suggestions will be appreciated.

JT