Increase precision for base conversion for large integers.

R=jkummerow@chromium.org
BUG=v8:3025
LOG=Y

Review URL: https://codereview.chromium.org/88583002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18082 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/conversions.cc

@@ -401,8 +401,9 @@ char* DoubleToRadixCString(double value, int radix) {
   // at least one digit.
   int integer_pos = kBufferSize - 2;
   do {
-    integer_buffer[integer_pos--] =
-        chars[static_cast<int>(fmod(integer_part, radix))];
+    double remainder = fmod(integer_part, radix);
+    integer_buffer[integer_pos--] = chars[static_cast<int>(remainder)];
+    integer_part -= remainder;
     integer_part /= radix;
   } while (integer_part >= 1.0);
   // Sanity check.

test/mjsunit/regress/regress-3025.js

+// Copyright 2013 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+var n = 0x8000000000000800;
+assertEquals(n, 9223372036854778000);
+var s = n.toString(5);
+var v = parseInt(s, 5);
+assertEquals(n, v);