Fix android application platform will crash problem.

If slide on password lock panel and repeatedly swith this
panel to lock panel with BACK button and POWER/HOME button,
the android application platform will crash.

1 files changed, 2 insertions, 0 deletions

diff --git a/core/java/com/android/internal/widget/LockPatternView.java b/core/java/com/android/internal/widget/LockPatternView.java
index 53be8911f375..bad7292b8f57 100644
--- a/core/java/com/android/internal/widget/LockPatternView.java
+++ b/core/java/com/android/internal/widget/LockPatternView.java
@@ -582,6 +582,8 @@ public class LockPatternView extends View {
                     mInProgressY = y;
 
                     if (mPatternInProgress) {
+                        if (mPattern.isEmpty()) return false;
+
                         final ArrayList<Cell> pattern = mPattern;
                         final float radius = mSquareWidth * mDiameterFactor * 0.5f;