From a41f48261da13728038dcfc2b027cc16e5ca5e1b Mon Sep 17 00:00:00 2001
From: Bas Leijdekkers <basleijdekkers@gmail.com>
Date: Fri, 22 Mar 2019 11:45:54 +0100
Subject: [PATCH] SSR: fix and improve new array expression matching
 (IDEA-209438)

---
 .../impl/matcher/JavaMatchingVisitor.java     | 40 ++++++++++++++-----
 .../StructuralSearchTest.java                 |  7 ++++
 2 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/java/structuralsearch-java/src/com/intellij/structuralsearch/impl/matcher/JavaMatchingVisitor.java b/java/structuralsearch-java/src/com/intellij/structuralsearch/impl/matcher/JavaMatchingVisitor.java
index c29c3c8e73f8..b8df818ef343 100644
--- a/java/structuralsearch-java/src/com/intellij/structuralsearch/impl/matcher/JavaMatchingVisitor.java
+++ b/java/structuralsearch-java/src/com/intellij/structuralsearch/impl/matcher/JavaMatchingVisitor.java
@@ -969,10 +969,21 @@ public class JavaMatchingVisitor extends JavaElementVisitor {
   }
 
   private void matchArrayOrArguments(final PsiNewExpression new1, final PsiNewExpression new2) {
+    final PsiType type1 = new1.getType();
+    final PsiType type2 = new2.getType();
+    if (!myMatchingVisitor.setResult(type1 != null && type2 != null && type1.getArrayDimensions() == type2.getArrayDimensions())) return;
+    final PsiArrayInitializerExpression initializer1 = new1.getArrayInitializer();
+    final PsiArrayInitializerExpression initializer2 = new2.getArrayInitializer();
+    if (initializer1 != null) {
+      if (!myMatchingVisitor.setResult(myMatchingVisitor.matchSons(initializer1, initializer2))) return;
+    }
+    else if (initializer2 != null) {
+      myMatchingVisitor.setResult(areZeroLiterals(new1.getArrayDimensions()) && initializer2.getInitializers().length == 0);
+      return;
+    }
+
     final PsiExpression[] dimensions1 = new1.getArrayDimensions();
     final PsiExpression[] dimensions2 = new2.getArrayDimensions();
-
-    if (!myMatchingVisitor.setResult(myMatchingVisitor.matchSons(new1.getArrayInitializer(), new2.getArrayInitializer()))) return;
     if (!myMatchingVisitor.setResult(dimensions1.length == dimensions2.length)) return;
     if (dimensions1.length != 0) {
       for (int i = 0; i < dimensions1.length; ++i) {
@@ -980,14 +991,18 @@ public class JavaMatchingVisitor extends JavaElementVisitor {
       }
     }
     else {
-      final PsiType type1 = new1.getType();
-      final PsiType type2 = new2.getType();
-      myMatchingVisitor.setResult(type1 != null && type2 != null && type1.getArrayDimensions() == type2.getArrayDimensions() &&
-                                  myMatchingVisitor.matchSons(new1.getArgumentList(), new2.getArgumentList()) &&
+      myMatchingVisitor.setResult(myMatchingVisitor.matchSons(new1.getArgumentList(), new2.getArgumentList()) &&
                                   myMatchingVisitor.setResult(matchTypeParameters(new1, new2)));
     }
   }
 
+  private static boolean areZeroLiterals(PsiExpression[] expressions) {
+    for (PsiExpression expression : expressions) {
+      if (!(expression instanceof PsiLiteralExpression) || !expression.getText().equals("0")) return false;
+    }
+    return true;
+  }
+
   private static boolean matchImplicitQualifier(PsiExpression qualifier, PsiElement reference, MatchContext context) {
     final PsiElement target = reference instanceof PsiMethodCallExpression
                               ? ((PsiMethodCallExpression)reference).resolveMethod()
@@ -1431,9 +1446,8 @@ public class JavaMatchingVisitor extends JavaElementVisitor {
     final PsiJavaCodeReferenceElement classReference = new1.getClassReference();
     if (other instanceof PsiArrayInitializerExpression &&
         other.getParent() instanceof PsiVariable &&
-        new1.getArrayDimensions().length == 0 &&
-        new1.getArrayInitializer() != null
-      ) {
+        areZeroLiterals(new1.getArrayDimensions())
+    ) {
       final MatchContext matchContext = myMatchingVisitor.getMatchContext();
       final CompiledPattern pattern = matchContext.getPattern();
       final boolean isTypedVar = pattern.isTypedVar(classReference);
@@ -1456,7 +1470,13 @@ public class JavaMatchingVisitor extends JavaElementVisitor {
         myMatchingVisitor.setResult(type != null && type.equals(otherType));
       }
       if (myMatchingVisitor.getResult()) {
-        myMatchingVisitor.matchSons(new1.getArrayInitializer(), other);
+        PsiArrayInitializerExpression initializer = new1.getArrayInitializer();
+        if (initializer != null) {
+          myMatchingVisitor.matchSons(initializer, other);
+        }
+        else {
+          myMatchingVisitor.setResult(((PsiArrayInitializerExpression)other).getInitializers().length == 0);
+        }
       }
       return;
     }
diff --git a/platform/structuralsearch/testSource/com/intellij/structuralsearch/StructuralSearchTest.java b/platform/structuralsearch/testSource/com/intellij/structuralsearch/StructuralSearchTest.java
index c79861f20844..c11d6b339ef9 100644
--- a/platform/structuralsearch/testSource/com/intellij/structuralsearch/StructuralSearchTest.java
+++ b/platform/structuralsearch/testSource/com/intellij/structuralsearch/StructuralSearchTest.java
@@ -248,6 +248,13 @@ public class StructuralSearchTest extends StructuralSearchTestCase {
                               "}}";
     assertEquals("Find 2 dimensional array", 1, findMatchesCount(multiDimensional, "new String[][]{}"));
     assertEquals("Find 1 dimensional arrays", 2, findMatchesCount(multiDimensional, "new String[]{}"));
+    assertEquals("Find empty 1 dimensional arrays", 2, findMatchesCount(multiDimensional, "new String[0]"));
+
+    String singleDimensional = "class X {{" +
+                               "  String[] ss1 = new String[0];" +
+                               "  String[][] ss2 = new String[0][];" +
+                               "}}";
+    assertEquals("Find empty array", 1, findMatchesCount(singleDimensional, "new String[0]"));
   }
 
   public void testLiteral() {