From ad807309afbba4e1ad8a1a34ea20e3054ae2b5c2 Mon Sep 17 00:00:00 2001
From: Tagir Valeev <Tagir.Valeev@jetbrains.com>
Date: Fri, 1 Dec 2017 13:28:36 +0700
Subject: [PATCH] IDEA-182933 Simplifying boolean condition removes necessary
 brackets and changes semantics

---
 .../fixture/SimplifyConcatWithParentheses.java      | 13 +++++++++++++
 .../SimplifyConcatWithParentheses_after.java        | 13 +++++++++++++
 .../java/codeInspection/DataFlowInspectionTest.java |  5 +++++
 .../src/com/siyeh/ig/psiutils/ParenthesesUtils.java |  3 ++-
 4 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 java/java-tests/testData/inspection/dataFlow/fixture/SimplifyConcatWithParentheses.java
 create mode 100644 java/java-tests/testData/inspection/dataFlow/fixture/SimplifyConcatWithParentheses_after.java

diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/SimplifyConcatWithParentheses.java b/java/java-tests/testData/inspection/dataFlow/fixture/SimplifyConcatWithParentheses.java
new file mode 100644
index 000000000000..e86a3f8e6da4
--- /dev/null
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/SimplifyConcatWithParentheses.java
@@ -0,0 +1,13 @@
+class Test {
+
+  // IDEA-182933
+  public static void main(String[] args) {
+    int a = 1;
+    int b = 2;
+    boolean f = false;
+
+    String s = "Hello " + (a + b) + (<warning descr="Condition 'f' is always 'false'"><caret>f</warning> ? " Earth" : " World");
+
+    System.out.println(s); // Prints Hello 3 World
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/SimplifyConcatWithParentheses_after.java b/java/java-tests/testData/inspection/dataFlow/fixture/SimplifyConcatWithParentheses_after.java
new file mode 100644
index 000000000000..d70db62bd520
--- /dev/null
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/SimplifyConcatWithParentheses_after.java
@@ -0,0 +1,13 @@
+class Test {
+
+  // IDEA-182933
+  public static void main(String[] args) {
+    int a = 1;
+    int b = 2;
+    boolean f = false;
+
+    String s = "Hello " + (a + b) + " World";
+
+    System.out.println(s); // Prints Hello 3 World
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java
index d03afaab2d18..8fc594731f48 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java
@@ -498,6 +498,11 @@ public class DataFlowInspectionTest extends DataFlowInspectionTestCase {
     checkIntentionResult("Simplify 'Test.valueOf(value) != null' to true extracting side effects");
   }
 
+  public void testSimplifyConcatWithParentheses() {
+    doTest();
+    checkIntentionResult("Simplify 'f' to false");
+  }
+
   public void testSideEffectWhile() {
     doTest();
     checkIntentionResult("Remove 'while' statement extracting side effects");
diff --git a/plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/psiutils/ParenthesesUtils.java b/plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/psiutils/ParenthesesUtils.java
index 065f26af9c94..3f16ccf3d734 100644
--- a/plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/psiutils/ParenthesesUtils.java
+++ b/plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/psiutils/ParenthesesUtils.java
@@ -309,7 +309,8 @@ public class ParenthesesUtils {
             return;
           }
         }
-        if (ignoreClarifyingParentheses) {
+        if (ignoreClarifyingParentheses ||
+            (parentOperator == JavaTokenType.PLUS && TypeUtils.isJavaLangString(parentType) && !TypeUtils.isJavaLangString(bodyType))) {
           if (parentOperator.equals(bodyOperator)) {
             removeParentheses(body, ignoreClarifyingParentheses);
           }