Good one. This exhibits the nearly same behavior under 5.8 on Linux. (I get a single character printed the second time around, though the string is still two bytes long.)

I poked at it a bit to put the parameters into temporaries, but got the same effect. I also tried using a different lexical variable for the second call, but still got the same effect. When I pull the characters out and do the XOR swap on them, I get the right result. That seems to point the finger at substr(). I wonder if some internal optimization has gone awry.

Time for a bug report.

In reply to Re: An obscure side effect? by dws
in thread An obscure side effect? by BrowserUk

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