From 7ec424fabd07282e273f2b74094d905dbfd2104c Mon Sep 17 00:00:00 2001
From: Pavel Dolgov <pavel.dolgov@jetbrains.com>
Date: Mon, 2 Apr 2018 12:58:08 +0300
Subject: [PATCH] Java: Handle chained assignment of fields in class
 initializer (IDEA-188872)

---
 .../defUse/DefUseInspectionBase.java          | 14 +++++++++++++
 .../defUse/ChainedFieldInitializer.java       | 21 +++++++++++++++++++
 .../java/codeInspection/DefUseTest.java       |  1 +
 3 files changed, 36 insertions(+)
 create mode 100644 java/java-tests/testData/inspection/defUse/ChainedFieldInitializer.java

diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/defUse/DefUseInspectionBase.java b/java/java-analysis-impl/src/com/intellij/codeInspection/defUse/DefUseInspectionBase.java
index 11f16c133b69..d621ce6e1422 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/defUse/DefUseInspectionBase.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/defUse/DefUseInspectionBase.java
@@ -140,6 +140,20 @@ public class DefUseInspectionBase extends AbstractBaseJavaLocalInspectionTool {
         final List<PsiAssignmentExpression> assignments = collectAssignments(field, classInitializer);
         if (!assignments.isEmpty()) {
           boolean isDefinitely = HighlightControlFlowUtil.variableDefinitelyAssignedIn(field, classInitializer.getBody());
+          if (isDefinitely) {
+            try {
+              ControlFlow flow = HighlightControlFlowUtil.getControlFlowNoConstantEvaluate(classInitializer.getBody());
+              if (ControlFlowUtil.getReadBeforeWrite(flow)
+                                 .stream()
+                                 .anyMatch(read -> (isStatic || ExpressionUtil.isEffectivelyUnqualified(read)) &&
+                                                   read.isReferenceTo(field))) {
+                isDefinitely = false;
+              }
+            }
+            catch (AnalysisCanceledException e) {
+              // ignore
+            }
+          }
           fieldWrites.add(FieldWrite.createAssignments(isDefinitely, assignments));
         }
       }
diff --git a/java/java-tests/testData/inspection/defUse/ChainedFieldInitializer.java b/java/java-tests/testData/inspection/defUse/ChainedFieldInitializer.java
new file mode 100644
index 000000000000..abcd58c8572c
--- /dev/null
+++ b/java/java-tests/testData/inspection/defUse/ChainedFieldInitializer.java
@@ -0,0 +1,21 @@
+import java.util.*;
+
+class Base {
+  protected Base(Map<String, Class<?>> aMap) {
+  }
+}
+
+class SubClass extends Base {
+  private static Map<String, Class<?>> aMap = new TreeMap<>();
+  static {
+    aMap = Collections.unmodifiableMap(aMap);
+  }
+  public SubClass() { super(aMap); }
+}
+
+class WithStatic {
+  private static int n = 1;
+  static {
+    n = n + 1;
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInspection/DefUseTest.java b/java/java-tests/testSrc/com/intellij/java/codeInspection/DefUseTest.java
index bae0a2e029a2..5cc2d9327c8d 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInspection/DefUseTest.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInspection/DefUseTest.java
@@ -59,6 +59,7 @@ public class DefUseTest extends LightCodeInsightFixtureTestCase {
   public void testNestedTryFinallyInEndlessLoop() { doTest(); }
   public void testNestedTryFinallyInForLoop() { doTest(); }
   public void testFieldInitializer() { doTest(); }
+  public void testChainedFieldInitializer() { doTest(); }
   public void testFieldIgnoringRedundantInitializer() {
     DefUseInspection inspection = new DefUseInspection();
     inspection.REPORT_REDUNDANT_INITIALIZER = false;