Merge "Fix digitsRequired() for negative denominators" into mnc-dev

2 files changed, 10 insertions, 1 deletions

diff --git a/src/com/android/calculator2/BoundedRational.java b/src/com/android/calculator2/BoundedRational.java
index 8bf2bf5..2602f56 100644
--- a/src/com/android/calculator2/BoundedRational.java
+++ b/src/com/android/calculator2/BoundedRational.java
@@ -485,6 +485,7 @@ public class BoundedRational {
     }
 
     private static final BigInteger BIG_FIVE = BigInteger.valueOf(5);
+    private static final BigInteger BIG_MINUS_ONE = BigInteger.valueOf(-1);
 
     // Return the number of decimal digits to the right of the
     // decimal point required to represent the argument exactly,
@@ -514,7 +515,9 @@ public class BoundedRational {
         // (Recall the fraction was in lowest terms to start with.)
         // Otherwise the powers of 10 we need to cancel the denominator
         // is the larger of powers_of_two and powers_of_five.
-        if (!den.equals(BigInteger.ONE)) return Integer.MAX_VALUE;
+        if (!den.equals(BigInteger.ONE) && !den.equals(BIG_MINUS_ONE)) {
+            return Integer.MAX_VALUE;
+        }
         return Math.max(powers_of_two, powers_of_five);
     }
 }
diff --git a/tests/src/com/android/calculator2/BRTest.java b/tests/src/com/android/calculator2/BRTest.java
index 29a5ae9..77d4bf0 100644
--- a/tests/src/com/android/calculator2/BRTest.java
+++ b/tests/src/com/android/calculator2/BRTest.java
@@ -139,6 +139,12 @@ public class BRTest extends TestCase {
         check(BR_0.signum() == 0, "signum(0)");
         check(BR_M1.signum() == -1, "signum(-1)");
         check(BR_2.signum() == 1, "signum(2)");
+        check(BoundedRational.digitsRequired(BoundedRational.ZERO) == 0, "digitsRequired(0)");
+        check(BoundedRational.digitsRequired(BoundedRational.HALF) == 1, "digitsRequired(1/2)");
+        check(BoundedRational.digitsRequired(BoundedRational.MINUS_HALF) == 1,
+                "digitsRequired(-1/2)");
+        check(BoundedRational.digitsRequired(new BoundedRational(1,-2)) == 1,
+                "digitsRequired(1/-2)");
         // We check values that include all interesting degree values.
         BoundedRational r = BR_M390;
         while (!r.equals(BR_390)) {