teach InitializationUtils about instanceof expressions

plugins/InspectionGadgets/src/com/siyeh/ig/psiutils/InitializationUtils.java

@@ -96,7 +96,8 @@ public class InitializationUtils {
     if (statement instanceof PsiBreakStatement ||
         statement instanceof PsiContinueStatement ||
         statement instanceof PsiAssertStatement ||
-        statement instanceof PsiEmptyStatement) {
+        statement instanceof PsiEmptyStatement ||
+        statement instanceof PsiSwitchLabelStatement) {
       return false;
     }
     else if (statement instanceof PsiReturnStatement) {
@@ -502,6 +503,11 @@ public class InitializationUtils {
       }
       return false;
     }
+    else if (expression instanceof PsiInstanceOfExpression) {
+      final PsiInstanceOfExpression instanceOfExpression = (PsiInstanceOfExpression)expression;
+      final PsiExpression operand = instanceOfExpression.getOperand();
+      return expressionAssignsVariableOrFails(operand, variable, checkedMethods, strict);
+    }
     else {
       return false;
     }

plugins/InspectionGadgets/test/com/siyeh/igtest/initialization/field/InstanceVariableInitialization.java

@@ -86,4 +86,11 @@ class B {
 
     }
   }
+}
+class C {
+  private Object o;
+
+  C() {
+    boolean b = (o = "") instanceof String;
+  }
 }