[Exim] regex problem (PCRE)

Hello,

I'm playing a bit with backward assertions in regexes using pcretest,
and have the following problem.
I need to match 'any line ending in '"' but not in '\"'.
So my regex looks like:

/(?<!\\)"$/

then:

re> /(?<!\\)"$/
data> fdsafsdfdfda"
0: "

which is ok, but

data> dfasdfdaf\"
0: "

which should not be ok. Now testing with another character:

/(?<!a)"$/

it works as expected:

re> /(?<!a)"$/
data> fadsfdaafda"
No match
data>

I know there are some pretty good regex gurus on this list, maybe
they can help here. Thanks in advance!

Bernard Stern, SWITCH

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