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Re^3: Really Odd Bug With LWP and Device::SerialPort

by runrig (Abbot)
on Aug 08, 2013 at 21:07 UTC ( #1048643=note: print w/replies, xml ) Need Help??

in reply to Re^2: Really Odd Bug With LWP and Device::SerialPort
in thread Really Odd Bug With LWP and Device::SerialPort

Well, there is some differences in the 'MAGIC' attributes before and after the substr (no MAGIC before, but MAGIC after) when you do Devel::Peek::Dump($data), but I don't know enough about that stuff to know what it means (non-magic unicode strings don't work with serial ports?).

This appears after the substr:

MAGIC = 0x6336a0 MG_VIRTUAL = &PL_vtbl_utf8 MG_TYPE = PERL_MAGIC_utf8(w) MG_LEN = -1

I would think that you might want to specify the encoding when writing to a serial port though.

Update: Sounds somewhat similar to this issue?

Replies are listed 'Best First'.
Re^4: Really Odd Bug With LWP and Device::SerialPort
by kschwab (Priest) on Aug 08, 2013 at 21:47 UTC
    Going down that line, the bug isn't triggered when pulling from an http:// url, but it IS triggered with an https:// (ssl) url. The output from Devel::Peek::Dump looks pretty much identical. Which I suppose means the answer isn't anywhere in MAGIC or utf8. Thanks for the pointers though.
    # Devel::Peek::Dump output with https url (triggers bug) SV = PVMG(0x2fbcc3c) at 0x25e7ff4 REFCNT = 1 FLAGS = (PADMY,SMG,POK,pPOK,UTF8) IV = 0 NV = 0 PV = 0x2ff7034 "<!DOCT"\0 [UTF8 "<!DOCT"] CUR = 6 LEN = 12 MAGIC = 0x2f9066c MG_VIRTUAL = &PL_vtbl_mglob MG_TYPE = PERL_MAGIC_regex_global(g) MG_LEN = -1 # Devel::Peek::Dump output with http url (doesn't trigger bug) SV = PVMG(0x2e25434) at 0x2567ff4 REFCNT = 1 FLAGS = (PADMY,SMG,POK,pPOK,UTF8) IV = 0 NV = 0 PV = 0x2fe7c5c "<!DOCT"\0 [UTF8 "<!DOCT"] CUR = 6 LEN = 12 MAGIC = 0x2d96af4 MG_VIRTUAL = &PL_vtbl_mglob MG_TYPE = PERL_MAGIC_regex_global(g) MG_LEN = -1
      Not sure I understand...the "MAGIC" doesn't appear (at least for me) until after the substr (when the bug is not triggered), and so I was postulating that maybe it's the lack of MAGIC that triggers the bug. I can't comment on what actually triggers the bug since I'm not using serial ports...
        I think we're on the same page. Basically, I can trigger the bug on strings both with, and without magic. Deep and mysterious enough that I think I'll give up and just keep my fix in place.

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