From: Paul Rubel <prubel@...>
Date: 2003-07-22T03:36:56+09:00
Subject: gsub(/\s*$/, "") doubling string

Hello,
 I recently downloaded ruby 1.8.0 p3, (2003-06-23) [i686-linux], and
tried it on some code that chopped trailing spaces from a string using
gsub(/\s*$/, ""). I'm seeing some odd behavior and was hoping someone
could shed some light on what's happening. 

 In 1.6.7 the code above did what I expected. However, in 1.8.0p3 it
seems to double the string if the string doesn't end in a space.

#does what I expected in 1.6 and 1.8
irb(main):004:0> " TEST   ".gsub(/\s*$/, "")
=> " TEST"

# very odd (at least to me) in 1.8.0p3
irb(main):005:0> " TEST   .".gsub(/\s*$/, "")
=> " TEST   . TEST   ." 

 Where does this repeat come from? If I change the * to a + it fixes my
problem but I was hoping someone could help explain why it's happening.

 While looking into this I've noticed that there seems to be something
special about 2 repeats. 

irb(main):002:0> "  string       ".gsub(/\s*$/, 'P')
"  stringPP"

 Regardless of how many trailing spaces I add two Ps are always
appended. It seems that one matches all the spaces and then one matches
the zero length string that's the end itself since a string without
trailing spaces puts in one P. Is the $ getting used twice in this
match?

 I'd appreciate any explanations or help.
   thank you,
     Paul