Have two-way binding use localized variables to prevent NPE.

Bug 26962999

Two-way binding was using the inverted expressions directly
without localizing variables. That meant that if there was
a variable set to null during evaluation, it may get a
NullPointerException even though it checked for null
on the value previously. This CL localizes the variables
so that cannot happen.

Change-Id: Ia55955ce0f1cb750e6a678e72e0cda03f0e3c9b6

1 files changed, 15 insertions, 5 deletions

diff --git a/compiler/src/main/java/android/databinding/tool/expr/UnaryExpr.java b/compiler/src/main/java/android/databinding/tool/expr/UnaryExpr.java
index 881a352c..18e5985f 100644
--- a/compiler/src/main/java/android/databinding/tool/expr/UnaryExpr.java
+++ b/compiler/src/main/java/android/databinding/tool/expr/UnaryExpr.java
@@ -36,17 +36,22 @@ public class UnaryExpr extends Expr {
 
     @Override
     protected String computeUniqueKey() {
-        return addTwoWay(join(getOpStr(), getExpr().getUniqueKey()));
+        return join(getOpStr(), getExpr().getUniqueKey());
     }
 
     @Override
-    public KCode toInverseCode(KCode value) {
-        return getExpr().toInverseCode(new KCode().app(mOp, value));
+    public Expr generateInverse(ExprModel model, Expr value, String bindingClassName) {
+        return model.unary(mOp, getExpr().generateInverse(model, value, bindingClassName));
     }
 
     @Override
-    protected KCode generateCode(boolean expand) {
-        return new KCode().app(getOp(), getExpr().toCode(expand));
+    public Expr cloneToModel(ExprModel model) {
+        return model.unary(mOp, getExpr().cloneToModel(model));
+    }
+
+    @Override
+    protected KCode generateCode() {
+        return new KCode().app(getOp(), getExpr().toCode());
     }
 
     @Override
@@ -76,4 +81,9 @@ public class UnaryExpr extends Expr {
     public Expr getExpr() {
         return getChildren().get(0);
     }
+
+    @Override
+    public String toString() {
+        return mOp + getExpr();
+    }
 }