Do not remove ||0 in non-boolean contexts

Author: zbynek

dev/core/src/com/google/gwt/dev/js/JsStaticEval.java

@@ -104,7 +104,7 @@ private static class MustExecVisitor extends JsVisitor {
 
     private final List<JsStatement> mustExec = new ArrayList<JsStatement>();
 
-    public MustExecVisitor() {
+    MustExecVisitor() {
     }
 
     @Override
@@ -184,7 +184,9 @@ public boolean visit(JsBinaryOperation x, JsContext ctx) {
         evalContext.put(x.getArg2(), evalContext.get(x));
       } else if (x.getOperator() == JsBinaryOperator.COMMA) {
         evalContext.put(x.getArg1(), EvalMode.VOID);
-        evalContext.put(x.getArg2(), evalContext.get(x));
+        if (evalContext.containsKey(x)) {
+          evalContext.put(x.getArg2(), evalContext.get(x));
+        }
       }
       return true;
     }
@@ -226,8 +228,12 @@ public void endVisit(JsBinaryOperation x, JsContext ctx) {
              break;
          }
       }
-      evalContext.remove(arg1);
-      evalContext.remove(arg2);
+      if (arg1 != result) {
+        evalContext.remove(arg1);
+      }
+      if (arg2 != result) {
+        evalContext.remove(arg2);
+      }
       result = maybeReorderOperations(result);
 
       if (result != x) {
@@ -667,7 +673,7 @@ protected static JsExpression shortCircuitAnd(JsBinaryOperation expr,
         return arg1;
       }
     }
-    if (arg2 instanceof CanBooleanEval && evalContext.containsKey(arg1)) {
+    if (arg2 instanceof CanBooleanEval && evalContext.containsKey(arg2)) {
       CanBooleanEval eval2 = (CanBooleanEval) arg2;
       if (eval2.isBooleanTrue() && !arg2.hasSideEffects()) {
         return arg1;
@@ -709,7 +715,7 @@ protected static JsExpression shortCircuitOr(JsBinaryOperation expr,
         return arg1;
       }
     }
-    if (arg2 instanceof CanBooleanEval && evalContext.containsKey(arg1)) {
+    if (arg2 instanceof CanBooleanEval && evalContext.containsKey(arg2)) {
       CanBooleanEval eval2 = (CanBooleanEval) arg2;
       if (eval2.isBooleanFalse() && !arg2.hasSideEffects()) {
         return arg1;

dev/core/test/com/google/gwt/dev/js/JsStaticEvalTest.java

@@ -163,6 +163,7 @@ public void testShortCircuitAnd() throws Exception {
     assertEquals("alert(a&&true);", optimize("alert(a && true)"));
     assertEquals("alert(a&&false);", optimize("alert(a && false)"));
     assertEquals("alert(!!a&&!!b);", optimize("alert(!!a && !!b)"));
+    assertEquals("alert(c|(bits&&1));", optimize("alert(c | (a, bits && 1))"));
 
     // in boolean context we can simplify more
     assertEquals("alert(a&&b?c:d);", optimize("alert(!!a && !!b ? c :d)"));
@@ -180,6 +181,11 @@ public void testShortCircuitAndWithSideEffects() throws Exception {
     assertEquals("a()&&c()?d():e();", optimize("a() && true && c() ? d() : e();"));
   }
 
+  public void testSimplifyComma() throws Exception {
+    assertEquals("alert(!!a());", optimize("alert((true, !!a()))"));
+    assertEquals("alert((a(),true));", optimize("alert((!!a(), true))"));
+  }
+
   public void testShortCircuitOr() throws Exception {
     assertEquals("alert(true);", optimize("alert(true || a)"));
     assertEquals("alert(a);", optimize("alert(false || a)"));
@@ -188,6 +194,7 @@ public void testShortCircuitOr() throws Exception {
     assertEquals("alert(a||true);", optimize("alert(a || true)"));
     assertEquals("alert(a||false);", optimize("alert(a || false)"));
     assertEquals("alert(!!a||!!b);", optimize("alert(!!a || !!b)"));
+    assertEquals("alert(c|(bits||0));", optimize("alert(c | (a, bits || 0))"));
 
     // in boolean context we can simplify more
     assertEquals("alert(a||b?c:d);", optimize("alert(!!a || !!b ? c :d)"));