cmsdk: Return UNKNOWN for impossible sdk ints.

Change-Id: I77a44abba0db223b031d6714c4fd8beb03a43cdc

src/java/cyanogenmod/os/Build.java

@@ -17,6 +17,7 @@
 package cyanogenmod.os;
 
 import android.os.SystemProperties;
+import android.text.TextUtils;
 import android.util.SparseArray;
 
 /**
@@ -84,9 +85,13 @@ public class Build {
     /**
      * Retrieve the name for the SDK int
      * @param sdkInt
-     * @return name of the SDK int
+     * @return name of the SDK int, {@link #UNKNOWN) if not known
      */
     public static String getNameForSDKInt(int sdkInt) {
-        return sdkMap.get(sdkInt);
+        final String name = sdkMap.get(sdkInt);
+        if (TextUtils.isEmpty(name)) {
+            return UNKNOWN;
+        }
+        return name;
     }
 }

tests/src/org/cyanogenmod/tests/versioning/unit/BuildTest.java

@@ -56,4 +56,11 @@ public class BuildTest extends AndroidTestCase {
         }
         assertEquals(0, i);
     }
+
+    @SmallTest
+    public void testSdkLevelRetrieveNameImpossible() {
+        String name = Build.getNameForSDKInt(Integer.MAX_VALUE);
+        assertNotNull(name);
+        assertEquals(Build.UNKNOWN, name);
+    }
 }