KT2482 fix - empty if codegen

compiler/backend/src/org/jetbrains/jet/codegen/ExpressionCodegen.java

@@ -244,7 +244,6 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
     @Override
     public StackValue visitIfExpression(JetIfExpression expression, StackValue receiver) {
         Type asmType = expressionType(expression);
-        StackValue condition = gen(expression.getCondition());
 
         JetExpression thenExpression = expression.getThen();
         JetExpression elseExpression = expression.getElse();
@@ -261,16 +260,19 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
                 StackValue.putTuple0Instance(v);
                 return StackValue.onStack(asmType);
             }
+            StackValue condition = gen(expression.getCondition());
             return generateSingleBranchIf(condition, elseExpression, false);
         }
         else {
             if (isEmptyExpression(elseExpression)) {
+                StackValue condition = gen(expression.getCondition());
                 return generateSingleBranchIf(condition, thenExpression, true);
             }
         }
 
 
         Label elseLabel = new Label();
+        StackValue condition = gen(expression.getCondition());
         condition.condJump(elseLabel, true, v);   // == 0, i.e. false
 
         Label end = new Label();

compiler/testData/codegen/regressions/kt2482.kt

@@ -0,0 +1,9 @@
+public fun box() : String {
+    if ( 0 == 0 ) { // Does not crash if either this...
+        if ( 0 == 0 ) { // ...or this is changed to if ( true )
+            // Does not crash if the following is uncommented.
+            //println("foo")
+        }
+    }
+    return "OK"
+}

compiler/tests/org/jetbrains/jet/codegen/ClassGenTest.java

@@ -486,4 +486,9 @@ public class ClassGenTest extends CodegenTestCase {
         createEnvironmentWithMockJdkAndIdeaAnnotations(ConfigurationKind.JDK_ONLY);
         blackBoxMultiFile("regressions/kt2485.kt");
     }
+
+    public void testKt2482() {
+        createEnvironmentWithMockJdkAndIdeaAnnotations(ConfigurationKind.JDK_ONLY);
+        blackBoxMultiFile("regressions/kt2482.kt");
+    }
 }