fixes a bug involuved in Pull Request #294

Readme.html

@@ -283,7 +283,7 @@ <h2>Changes</h2>
 
 <p>-version 3.27
 <ul>
-   <li>GitHub Issue #271 (PR #279), #280 (PR #281), and #282.
+   <li>GitHub Issue #271 (PR #279), #280 (PR #281), #282, and PR #294.
 </ul>
 
 <p>-version 3.26 on October 3, 2019

src/main/javassist/compiler/MemberCodeGen.java

@@ -365,7 +365,7 @@ private void atNewArrayExpr2(int type, ASTree sizeExpr,
                 sizeExpr.accept(this);
         else
             if (sizeExpr == null) {
-                int s = init.length();
+                int s = init.size();
                 bytecode.addIconst(s);
             }
             else
@@ -414,7 +414,7 @@ private void atNewArrayExpr2(int type, ASTree sizeExpr,
         }
 
         if (init != null) {
-            int s = init.length();
+            int s = init.size();
             ASTList list = init;
             for (int i = 0; i < s; i++) {
                 bytecode.addOpcode(DUP);

src/main/javassist/compiler/Parser.java

@@ -683,7 +683,7 @@ private ArrayInit parseArrayInitializer(SymbolTable tbl)
         lex.get();      // '{'
         if(lex.lookAhead() == '}'){
             lex.get();
-            return new ArrayInit(new IntConst(0,TokenId.IntConstant));
+            return new ArrayInit(null);
         }
         ASTree expr = parseExpression(tbl);
         ArrayInit init = new ArrayInit(expr);

src/main/javassist/compiler/ast/ArrayInit.java

@@ -25,10 +25,27 @@ public class ArrayInit extends ASTList {
     /** default serialVersionUID */
     private static final long serialVersionUID = 1L;
 
+    /**
+     * Constructs an object.
+     * @param firstElement      maybe null when the initializer is <code>{}</code> (empty).
+     */
     public ArrayInit(ASTree firstElement) {
         super(firstElement);
     }
 
+    /**
+     * Gets the number of the elements.  Don't call {@link #length()}.
+     *
+     * @return the number of the elements.
+     */
+    public int size() {
+        int s = length();
+        if (s == 1 && head() == null)
+            return 0;
+        else
+            return s;
+    }
+
     @Override
     public void accept(Visitor v) throws CompileError { v.atArrayInit(this); }
 

src/test/javassist/JvstTest5.java

@@ -558,4 +558,20 @@ public void testRedundantInsertAfter() throws Exception {
         Object obj = make(cc.getName());
         assertEquals(71 + 22, invoke(obj, "run"));
     }
+
+    // PR #294
+    public void testEmptyArrayInit() throws Exception {
+        CtClass cc = sloader.makeClass("test5.EmptyArrayInit");
+        CtMethod m = CtNewMethod.make("public int[] foo(){ int[] a = {}; return a; }", cc);
+        cc.addMethod(m);
+        CtMethod m2 = CtNewMethod.make("public int[] bar(){ int[] a = new int[]{}; return a; }", cc);
+        cc.addMethod(m2);
+        CtMethod m3 = CtNewMethod.make("public String[] baz(){ String[] a = { null }; return a; }", cc);
+        cc.addMethod(m3);
+        CtMethod m0 = CtNewMethod.make("public int run() { return foo().length + bar().length + baz().length; }", cc);
+        cc.addMethod(m0);
+        cc.writeFile();
+        Object obj = make(cc.getName());
+        assertEquals(1, invoke(obj, "run"));
+    }
 }