Description of problem:

The following Perl script generates an assertion failure:

$ perl -e 'BEGIN { $::{A} = \1 }; index "", A; *B = $::{A}'
Assertion ((((shplep)->sv_flags & (0x00004000|0x00008000)) == 0x00008000) && (((svtype)((shplep)->sv_flags & 0xff)) == SVt_PVGV || ((svtype)((shplep)->sv_flags & 0xff)) == SVt_PVLV)) failed: file "sv.c", line 3212 at -e line 1.

Removing the index statement clears the error:

$ perl -e 'BEGIN { $::{A} = \1 }; *B = $::{A}'
# no error

Version-Release number of selected component (if applicable):

$ rpm -q perl
perl-5.10.0-34.fc9.i386


Additional info:

The BEGIN block is effectively equivalent to:

  use constant A => 1;

This also generates the same error.

index does not need to be executed, it merely has to be used on A somewhere in the script. For instance:

  index "", A if 0;

produces the same error. The problem appears to be related to Perl's upgrading of the constant to attach Boyer-Moore magic:

$ perl -mDevel::Peek=Dump -e 'BEGIN { $::{A} = \1 } Dump $::{A}'  # good
SV = RV(0x9638200) at 0x96381f4
  REFCNT = 1
  FLAGS = (ROK)
  RV = 0x9638234
  SV = IV(0x9638230) at 0x9638234
    REFCNT = 1
    FLAGS = (IOK,READONLY,pIOK)
    IV = 1
$ perl -mDevel::Peek=Dump -e 'BEGIN { $::{A} = \1 } index "", A if 0; Dump $::{A}'  # bad
SV = RV(0x80a1208) at 0x80a11fc
  REFCNT = 1
  FLAGS = (ROK)
  RV = 0x80a123c
  SV = PVGV(0x8099720) at 0x80a123c
    REFCNT = 2
    FLAGS = (PADTMP,SMG,POK,READONLY,pPOK,VALID,EVALED)
    IV = 100
    PV = 0x80a56ac "1"\0
    CUR = 1
    LEN = 4
    MAGIC = 0x80a9fb4
      MG_VIRTUAL = &PL_vtbl_bm
      MG_TYPE = PERL_MAGIC_bm(B)
    FLAGS = 0
    RARE = 49
    PREVIOUS = 0
    USEFUL = 100