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| author | Father Chrysostomos <sprout@cpan.org> | 2015-03-27 09:23:41 -0700 |
|---|---|---|
| committer | Father Chrysostomos <sprout@cpan.org> | 2015-03-27 12:30:22 -0700 |
| commit | 71622e40793536aa4f2ace7ffc704cc78151fd26 (patch) | |
| tree | 0c96ea53aeab1fdec2e092a1bc5c8df477b54a83 | |
| parent | d1d50e3e86916d266355a8fe5c5374460f7aa033 (diff) | |
| download | perl-71622e40793536aa4f2ace7ffc704cc78151fd26.tar.gz | |
Stop $^H |= 0x1c020000 from enabling all features
That set of bits sets the feature bundle to ‘custom’, which means that
the features are set by %^H, and also indicates that %^H has been did-
dled with, so it’s worth looking at.
In the specific case where %^H is untouched and there is no corres-
ponding cop hint hash behind the scenes, Perl_feature_is_enabled (in
toke.c) ends up returning TRUE.
Commit v5.15.6-55-g94250ae sped up feature checking by allowing
refcounted_he_fetch to return a boolean when checking for existence,
instead of converting the value to a scalar, whose contents we are not
even going to use.
This was when the bug started happening. I did not update the code
path in refcounted_he_fetch that handles the absence of a hint hash.
So it was returning &PL_sv_placeholder instead of NULL; TRUE instead
of FALSE.
This did not cause problems for most code, but with the introduction
of the new bitwise ops in v5.21.8-150-g8823cb8, it started causing
uni::perl to fail, because they were implicitly enabled, making ^ a
numeric op, when it was being used as a string op.
| -rw-r--r-- | hv.c | 3 | ||||
| -rw-r--r-- | t/lib/feature/bundle | 8 |
2 files changed, 10 insertions, 1 deletions
@@ -3189,7 +3189,7 @@ Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he *chain, Perl_croak(aTHX_ "panic: refcounted_he_fetch_pvn bad flags %"UVxf, (UV)flags); if (!chain) - return &PL_sv_placeholder; + goto ret; if (flags & REFCOUNTED_HE_KEY_UTF8) { /* For searching purposes, canonicalise to Latin-1 where possible. */ const char *keyend = keypv + keylen, *p; @@ -3249,6 +3249,7 @@ Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he *chain, return sv_2mortal(refcounted_he_value(chain)); } } + ret: return flags & REFCOUNTED_HE_EXISTS ? NULL : &PL_sv_placeholder; } diff --git a/t/lib/feature/bundle b/t/lib/feature/bundle index a5a67846c9..b9facc0bd6 100644 --- a/t/lib/feature/bundle +++ b/t/lib/feature/bundle @@ -117,3 +117,11 @@ EXPECT Use of assignment to $[ is deprecated at - line 2. Assigning non-zero to $[ is no longer possible at - line 5. b +######## +# NAME $^H accidentally enabling all features +eval 'BEGIN { $^H |= 0x1c020000 } $_ = evalbytes 12345'; +print $_||$@; +EXPECT +Number found where operator expected at (eval 1) line 1, near "evalbytes 12345" + (Do you need to predeclare evalbytes?) +syntax error at (eval 1) line 1, near "evalbytes 12345" |