Fix a bug spotted by Chris in my BigInteger patch; thanks!

The problem was this:
  Console.WriteLine(Int64.Parse("08000000000000000", NumberStyles.HexNumber));
  // => -9223372036854775808
  Console.WriteLine(Int64.Parse("9223372036854775808"));
  // => Value was either too large or too small for an Int64.

In other words, large hex numbers are interpreted as a sequence of bits, not as
an actual number.

1 files changed, 14 insertions, 0 deletions

diff --git a/Test/dafny4/LargeConstants.dfy b/Test/dafny4/LargeConstants.dfy
new file mode 100644
index 00000000..18435c30
--- /dev/null
+++ b/Test/dafny4/LargeConstants.dfy
@@ -0,0 +1,14 @@
+// RUN: %dafny /compile:0 /dprint:"%t.dprint" "%s" > "%t"

+// RUN: %diff "%s.expect" "%t"

+

+lemma largeIsLarge()

+  ensures 0x8000000000000000 > 0 {

+}

+

+lemma SmallIsSmall()

+  ensures -0x8000000000000000 < 0 {

+}

+

+lemma ShouldCancelOut()

+  ensures -0x8000000000000000 + 0x8000000000000000 == 0 {

+}