stop replacement chain calls to sequences when root type changes during call chain; this-chain is not supported though

plugins/IntentionPowerPak/src/com/siyeh/ipp/concatenation/MethodCallChainPredicate.java

@@ -45,52 +45,45 @@ class MethodCallChainPredicate implements PsiElementPredicate {
   }
 
   private static boolean isCallChain(PsiElement element) {
-    PsiClass aClass1 = getQualifierExpressionType(element);
-    if (aClass1 == null) {
+    PsiClassType aClassType1 = getQualifierExpressionType(element);
+    if (aClassType1 == null) {
       return false;
     }
     boolean first = true;
-    while (aClass1 != null) {
+    while (true) {
       final PsiMethodCallExpression methodCallExpression = (PsiMethodCallExpression)element;
       final PsiReferenceExpression methodExpression = methodCallExpression.getMethodExpression();
       final PsiExpression qualifierExpression = methodExpression.getQualifierExpression();
-      PsiClass aClass2 = getQualifierExpressionType(qualifierExpression);
+      PsiClassType expressionType = getQualifierExpressionType(qualifierExpression);
       if (!first) {
-        if (aClass2 == null) {
+        if (expressionType == null) {
+          if (qualifierExpression instanceof PsiMethodCallExpression &&
+              ((PsiMethodCallExpression)qualifierExpression).getMethodExpression().getQualifierExpression() == null) {
+            return false;
+          }
           return true;
         }
       } else {
         first = false;
       }
-      if (!aClass1.equals(aClass2)) {
+      if (!aClassType1.equals(expressionType)) {
         return false;
       }
-      aClass1 = aClass2;
+      aClassType1 = expressionType;
       element = qualifierExpression;
     }
-    return true;
   }
 
   @Nullable
-  private static PsiClass getQualifierExpressionType(PsiElement element) {
+  private static PsiClassType getQualifierExpressionType(PsiElement element) {
     if (!(element instanceof PsiMethodCallExpression)) {
       return null;
     }
+
     final PsiMethodCallExpression methodCallExpression = (PsiMethodCallExpression)element;
-    final PsiMethod method = methodCallExpression.resolveMethod();
-    if (method != null) {
-      return method.getContainingClass();
-    }
     final PsiReferenceExpression methodExpression = methodCallExpression.getMethodExpression();
     final PsiExpression qualifierExpression = methodExpression.getQualifierExpression();
-    if (!(qualifierExpression instanceof PsiMethodCallExpression)) {
-      return null;
-    }
-    final PsiType type = qualifierExpression.getType();
-    if (!(type instanceof PsiClassType)) {
-      return null;
-    }
-    final PsiClassType classType = (PsiClassType)type;
-    return classType.resolve();
+    final PsiType type = qualifierExpression != null ? qualifierExpression.getType() : null;
+    return type instanceof PsiClassType ? (PsiClassType)type : null;
   }
 }

plugins/IntentionPowerPak/test/com/siyeh/ipp/concatenation/call_chain/Builder.java

@@ -0,0 +1,6 @@
+class Test {
+  {
+    StringBuilder text = null;
+    text.delete(text.length() - 1, text.length()).ap<caret>pend(";\n");
+  }
+}

plugins/IntentionPowerPak/test/com/siyeh/ipp/concatenation/call_chain/Builder_after.java

@@ -0,0 +1,7 @@
+class Test {
+  {
+    StringBuilder text = null;
+      text.delete(text.length() - 1, text.length());
+      text.append(";\n");
+  }
+}

plugins/IntentionPowerPak/test/com/siyeh/ipp/concatenation/call_chain/ThisCollapse.java

@@ -0,0 +1,12 @@
+class FooBar<T> {
+  FooBar<List<T>> foo() {
+    return null;
+  }
+
+  FooBar<T> bar() {return this;}
+
+  void f(FooBar<String> fb) {
+    foo().bar().toSt<caret>ring();
+  }
+
+}

plugins/IntentionPowerPak/test/com/siyeh/ipp/concatenation/call_chain/Transformation.java

@@ -0,0 +1,12 @@
+class FooBar<T> {
+  <K> FooBar<K> foo(K k) {
+    return null;
+  }
+
+  FooBar<T> bar() {return this;}
+
+  void f(FooBar<String> fb) {
+    fb.foo(1).bar().toSt<caret>ring();
+  }
+
+}

plugins/IntentionPowerPak/testSrc/com/siyeh/ipp/concatenation/MakeCallChainIntoCallSequenceTest.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2000-2014 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.siyeh.ipp.concatenation;
+
+import com.siyeh.IntentionPowerPackBundle;
+import com.siyeh.ipp.IPPTestCase;
+
+public class MakeCallChainIntoCallSequenceTest extends IPPTestCase {
+
+  public void testBuilder() { doTest(); }
+  public void testTransformation() { assertIntentionNotAvailable();}
+  //should be probably possible?
+  public void testThisCollapse() { assertIntentionNotAvailable();}
+
+  @Override
+  protected String getIntentionName() {
+    return IntentionPowerPackBundle.message("make.call.chain.into.call.sequence.intention.name");
+  }
+
+  @Override
+  protected String getRelativePath() {
+    return "concatenation/call_chain";
+  }
+}