Fix issue 148. The results for sign comparison for BigRational.CompareTo was

wrong.

3 files changed, 46 insertions, 4 deletions

diff --git a/Binaries/DafnyRuntime.cs b/Binaries/DafnyRuntime.cs
index 3002d832..587d5159 100644
--- a/Binaries/DafnyRuntime.cs
+++ b/Binaries/DafnyRuntime.cs
@@ -1253,13 +1253,13 @@ namespace Dafny
       int asign = this.num.Sign;
       int bsign = that.num.Sign;
       if (asign < 0 && 0 <= bsign) {
-        return 1;
+        return -1;
       } else if (asign <= 0 && 0 < bsign) {
-        return 1;
-      } else if (bsign < 0 && 0 <= asign) {
         return -1;
+      } else if (bsign < 0 && 0 <= asign) {
+        return 1;
       } else if (bsign <= 0 && 0 < asign) {
-        return -1;
+        return 1;
       }
       BigInteger aa, bb, dd;
       Normalize(this, that, out aa, out bb, out dd);
diff --git a/Test/dafny4/Bug148.dfy b/Test/dafny4/Bug148.dfy
new file mode 100644
index 00000000..b7a08952
--- /dev/null
+++ b/Test/dafny4/Bug148.dfy
@@ -0,0 +1,25 @@
+// RUN: %dafny /compile:3  "%s" > "%t"

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

+

+method Main()

+{

+    var zero    : real  := 0.0;

+		var three   : real  := 3.0;

+    var fifteen : real  := 15.0;

+		var negone  : real  := -1.0;

+		var negthree : real := -3.0;

+		

+		print zero <= fifteen, "\n";  // true

+		print fifteen <= zero, "\n";  // false

+		print negone <= zero, "\n";   // true

+		print zero <= negone, "\n";   // false

+		print negone <= fifteen, "\n"; // true

+		print fifteen <= negone, "\n";  // false

+

+		print zero >= fifteen, "\n";  // false

+		print fifteen >= zero, "\n";  // true

+		print negone >= zero, "\n";   // false

+		print zero >= negone, "\n";   // true

+		print negone >= fifteen, "\n"; // false

+		print fifteen >= negone, "\n";  // true

+}

diff --git a/Test/dafny4/Bug148.dfy.expect b/Test/dafny4/Bug148.dfy.expect
new file mode 100644
index 00000000..7acfb169
--- /dev/null
+++ b/Test/dafny4/Bug148.dfy.expect
@@ -0,0 +1,17 @@
+

+Dafny program verifier finished with 2 verified, 0 errors

+Program compiled successfully

+Running...

+

+True
+False
+True
+False
+True
+False
+False
+True
+False
+True
+False
+True