From d54e1dead488e17ae4a5e02890795912e7654406 Mon Sep 17 00:00:00 2001
From: Peter John Acklam <pjacklam@online.no>
Date: Fri, 17 Apr 2015 21:28:37 +0200
Subject: [PATCH] Correct Math::BigInt -> new() for non-integer input.

The documentation in Math::BigInt says about input values that "Non-integer
values result in NaN." The actual behaviour doesn't comply with this.

- All input values in the range (-1,1) written as a decimal number, e.g.,
  -0.75 and 0.5, now return NaN, not 0.

- Input values with a large (absolute value) negative exponent, e.g.,
  1e-9999999, now return NaN. The former behaviour was to die with the
  message "Quantifier in {,} bigger than 32766 in regex; marked by ..."

- This patch fixes CPAN RT #61887 and CPAN RT #63038.
---
 dist/Math-BigInt/lib/Math/BigInt.pm | 16 +++++++++++-----
 dist/Math-BigInt/t/bigintpm.inc     |  4 ++--
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/dist/Math-BigInt/lib/Math/BigInt.pm b/dist/Math-BigInt/lib/Math/BigInt.pm
index 62f1be9..763b3f4 100644
--- a/dist/Math-BigInt/lib/Math/BigInt.pm
+++ b/dist/Math-BigInt/lib/Math/BigInt.pm
@@ -626,9 +626,13 @@ sub new
     elsif ($e < 0)
       {
       # xE-y, and empty mfv
-      #print "xE-y\n";
-      $e = abs($e);
-      if ($$miv !~ s/0{$e}$//)		# can strip so many zero's?
+      # Split the mantissa at the decimal point. E.g., if
+      # $$miv = 12345 and $e = -2, then $frac = 45 and $$miv = 123.
+
+      my $frac = substr($$miv, $e);     # $frac is fraction part
+      substr($$miv, $e) = "";           # $$miv is now integer part
+
+      if ($frac =~ /[^0]/)
         {
         if ($_trap_nan)
           {
@@ -640,8 +644,10 @@ sub new
         }
       }
     }
-  $self->{sign} = '+' if $$miv eq '0';			# normalize -0 => +0
-  $self->{value} = $CALC->_new($$miv) if $self->{sign} =~ /^[+-]$/;
+  unless ($self->{sign} eq $nan) {
+      $self->{sign} = '+' if $$miv eq '0';		# normalize -0 => +0
+      $self->{value} = $CALC->_new($$miv) if $self->{sign} =~ /^[+-]$/;
+  }
   # if any of the globals is set, use them to round and store them inside $self
   # do not round for new($x,undef,undef) since that is used by MBF to signal
   # no rounding
diff --git a/dist/Math-BigInt/t/bigintpm.inc b/dist/Math-BigInt/t/bigintpm.inc
index c3e815c..fa320b0 100644
--- a/dist/Math-BigInt/t/bigintpm.inc
+++ b/dist/Math-BigInt/t/bigintpm.inc
@@ -1091,6 +1091,8 @@ E23:NaN
 -1010E-2:NaN
 -1.01E+1:NaN
 -1.01E-1:NaN
+1E-999999:NaN
+0.5:NaN
 &bnan
 1:NaN
 2:NaN
@@ -2409,8 +2411,6 @@ inf:-inf:NaN
 15241:2:123
 144:2:12
 12:2:3
-0.49:2:0
-0.0049:2:0
 # invalid ones
 1:NaN:NaN
 -1:NaN:NaN
-- 
2.1.4