Re: [ID 20000912.008] substr replacement of tainted data (bug)

Message-ID: <14808.56336.594486.626712@busy.netsoft.ro>

p4raw-id: //depot/perl@7111

diff --git a/op.c b/op.c
index 4856d98..84a1df9 100644 (file)
--- a/op.c
+++ b/op.c
@@ -6463,6 +6463,22 @@ Perl_ck_trunc(pTHX_ OP *o)
     return ck_fun(o);
 }
 
+OP *
+Perl_ck_substr(pTHX_ OP *o)
+{
+    o = ck_fun(o);
+    if ((o->op_flags & OPf_KIDS) && o->op_private == 4) {
+       OP *kid = cLISTOPo->op_first;
+
+       if (kid->op_type == OP_NULL)
+           kid = kid->op_sibling;
+       if (kid)
+           kid->op_flags |= OPf_MOD;
+
+    }
+    return o;
+}
+
 /* A peephole optimizer.  We visit the ops in the order they're to execute. */
 
 void

diff --git a/opcode.pl b/opcode.pl
index d138917..43d98ae 100755 (executable)
--- a/opcode.pl
+++ b/opcode.pl
@@ -515,7 +515,7 @@ abs         abs                     ck_fun          fsTu%   S?
 # String stuff.
 
 length         length                  ck_lengthconst  isTu%   S?
-substr         substr                  ck_fun          st@     S S S? S?
+substr         substr                  ck_substr       st@     S S S? S?
 vec            vec                     ck_fun          ist@    S S S
 
 index          index                   ck_index        isT@    S S S?

diff --git a/t/op/substr.t b/t/op/substr.t
index 891e904..4d3bbce 100755 (executable)
--- a/t/op/substr.t
+++ b/t/op/substr.t
@@ -1,6 +1,6 @@
 #!./perl
 
-print "1..135\n";
+print "1..136\n";
 
 #P = start of string  Q = start of substr  R = end of substr  S = end of string
 
@@ -297,3 +297,10 @@ ok 125, $a eq 'xxxxefgh';
     ok 134, length($z) == 5;
     ok 135, $z eq "21\x{263a}10";
 }
+
+# replacement should work on magical values
+require Tie::Scalar;
+my %data;
+tie $data{'a'}, 'Tie::StdScalar';  # makes $data{'a'} magical
+$data{a} = "firstlast";
+ok 136, substr($data{'a'}, 0, 5, "") eq "first" && $data{'a'} eq "last";