Here is the answer to your question: in the second case, you see the effect of an optimization called "tail recursion". Suggestion: if it is possible, don't use capturing brackets inside atomic blocks.
Thanks a lot, Zoltan! Can you explain, why capturing atomic groups with capturing brackets inside can't produce tail recursion in cases when '(?:' can do this? Best regards --## List details at https://lists.exim.org/mailman/listinfo/pcre-dev
