From 14d26b44a1d7eee67837ec0ea8fb0368ac6fe33e Mon Sep 17 00:00:00 2001
From: Tony Cook <tony@develop-help.com>
Date: Tue, 20 Aug 2019 15:43:05 +1000
Subject: [PATCH] (perl #134230) don't interpret 0x, 0b when numifying strings
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Signed-off-by: Petr Písař <ppisar@redhat.com>
---
 numeric.c  | 9 +++++++++
 t/op/int.t | 5 ++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/numeric.c b/numeric.c
index f5eadc8173..fae2eb3c6d 100644
--- a/numeric.c
+++ b/numeric.c
@@ -1551,6 +1551,15 @@ Perl_my_atof3(pTHX_ const char* orig, NV* value, const STRLEN len)
         if ((endp = S_my_atof_infnan(aTHX_ s, negative, send, value)))
             return endp;
 
+        /* strtold() accepts 0x-prefixed hex and in POSIX implementations,
+           0b-prefixed binary numbers, which is backward incompatible
+        */
+        if ((len == 0 || len >= 2) && *s == '0' &&
+            (isALPHA_FOLD_EQ(s[1], 'x') || isALPHA_FOLD_EQ(s[1], 'b'))) {
+            *value = 0;
+            return (char *)s+1;
+        }
+
         /* If the length is passed in, the input string isn't NUL-terminated,
          * and in it turns out the function below assumes it is; therefore we
          * create a copy and NUL-terminate that */
diff --git a/t/op/int.t b/t/op/int.t
index 7e936da68d..b730ab2672 100644
--- a/t/op/int.t
+++ b/t/op/int.t
@@ -7,7 +7,7 @@ BEGIN {
     require Config;
 }
 
-plan 17;
+plan 19;
 
 # compile time evaluation
 
@@ -83,3 +83,6 @@ SKIP:
         cmp_ok($x, "==", int($x), "check $x == int($x)");
     }
 }
+
+is(1+"0x10", 1, "check string '0x' prefix not treated as hex");
+is(1+"0b10", 1, "check string '0b' prefix not treated as binary");
-- 
2.21.0