From 504c2c3867ffd7d2cc78fbb16479917821c37e8e Mon Sep 17 00:00:00 2001
From: anna <Anna.Kozlova@jetbrains.com>
Date: Tue, 30 Apr 2013 15:23:36 +0200
Subject: [PATCH] generics: do not prefer type with more bounds when additional
 bounds are just subtypes of the rest (IDEA-67668)

---
 .../JavaMethodsConflictResolver.java          | 63 +++++++++++++------
 .../AmbiguousMethodCallIDEA67668.java         | 17 +++++
 .../daemon/LightAdvHighlightingJdk7Test.java  |  1 +
 3 files changed, 61 insertions(+), 20 deletions(-)
 create mode 100644 java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting7/AmbiguousMethodCallIDEA67668.java

diff --git a/java/java-psi-impl/src/com/intellij/psi/scope/conflictResolvers/JavaMethodsConflictResolver.java b/java/java-psi-impl/src/com/intellij/psi/scope/conflictResolvers/JavaMethodsConflictResolver.java
index 0eace78fea45..6f1b08d3e3ca 100644
--- a/java/java-psi-impl/src/com/intellij/psi/scope/conflictResolvers/JavaMethodsConflictResolver.java
+++ b/java/java-psi-impl/src/com/intellij/psi/scope/conflictResolvers/JavaMethodsConflictResolver.java
@@ -630,28 +630,31 @@ public class JavaMethodsConflictResolver implements PsiConflictResolver{
                                            PsiType type2,
                                            PsiTypeParameter p1,
                                            PsiTypeParameter p2) {
-    Specifics specifics = checkSubtyping(TypeConversionUtil.erasure(PsiSubstitutor.EMPTY.substitute(p1)),
-                                         TypeConversionUtil.erasure(PsiSubstitutor.EMPTY.substitute(p2)), method1, method2);
-    if (specifics == Specifics.NEITHER) {
-      final Set<PsiElement> resolved1 = new HashSet<PsiElement>();
-      for (PsiJavaCodeReferenceElement referenceElement : p1.getExtendsList().getReferenceElements()) {
-        final PsiElement resolve = referenceElement.resolve();
-        if (resolve != null) {
-          resolved1.add(resolve);
-        }
+    final Set<PsiClass> resolved1 = new HashSet<PsiClass>();
+    for (PsiClassType referenceElement : p1.getExtendsList().getReferencedTypes()) {
+      final PsiClass resolve = referenceElement.resolve();
+      if (resolve != null) {
+        resolved1.add(resolve);
       }
-
-      final Set<PsiElement> resolved2 = new HashSet<PsiElement>();
-      for (PsiJavaCodeReferenceElement referenceElement : p2.getExtendsList().getReferenceElements()) {
-        final PsiElement resolve = referenceElement.resolve();
-        if (resolve != null) {
-          resolved2.add(resolve);
-        }
-      }
-
-      if (resolved1.size() > resolved2.size() && resolved1.containsAll(resolved2)) return Specifics.FIRST;
-      if (resolved2.size() > resolved1.size() && resolved2.containsAll(resolved1)) return Specifics.SECOND;
     }
+
+    final Set<PsiClass> resolved2 = new HashSet<PsiClass>();
+    for (PsiClassType referenceElement : p2.getExtendsList().getReferencedTypes()) {
+      final PsiClass resolve = referenceElement.resolve();
+      if (resolve != null) {
+        resolved2.add(resolve);
+      }
+    }
+
+    Specifics specifics = null;
+    if (resolved1.size() > resolved2.size()){
+      specifics = checkExtendsList(resolved1, resolved2, Specifics.FIRST);
+    } else if (resolved2.size() > resolved1.size()) {
+      specifics = checkExtendsList(resolved2, resolved1, Specifics.SECOND);
+    }
+    if (specifics != null) return specifics;
+    specifics = checkSubtyping(TypeConversionUtil.erasure(PsiSubstitutor.EMPTY.substitute(p1)),
+                               TypeConversionUtil.erasure(PsiSubstitutor.EMPTY.substitute(p2)), method1, method2);
     if (specifics != null) {
       return specifics;
     } else {               
@@ -661,6 +664,26 @@ public class JavaMethodsConflictResolver implements PsiConflictResolver{
     }
   }
 
+  private static Specifics checkExtendsList(Set<PsiClass> resolved1,
+                                            Set<PsiClass> resolved2,
+                                            Specifics preferred) {
+    if (resolved1.containsAll(resolved2)){
+      resolved1.removeAll(resolved2);
+      for (Iterator<PsiClass> iterator = resolved1.iterator(); iterator.hasNext(); ) {
+        PsiClass psiClass = iterator.next();
+        for (PsiClass aClass : resolved2) {
+          if (InheritanceUtil.isInheritorOrSelf(aClass, psiClass, true)) {
+            iterator.remove();
+            break;
+          }
+        }
+      }
+      if (!resolved1.isEmpty()) return preferred;
+      return Specifics.NEITHER;
+    }
+    return null;
+  }
+
   private PsiSubstitutor calculateMethodSubstitutor(final PsiTypeParameter[] typeParameters,
                                                     final PsiType[] types1,
                                                     final PsiType[] types2,
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting7/AmbiguousMethodCallIDEA67668.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting7/AmbiguousMethodCallIDEA67668.java
new file mode 100644
index 000000000000..2de2b0e4f5d9
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting7/AmbiguousMethodCallIDEA67668.java
@@ -0,0 +1,17 @@
+import java.util.Collection;
+import java.util.List;
+
+interface A
+{
+    <S extends Collection<?> & List<?>> void foo(S x);
+    <S extends List<?>> void foo(S x);
+}
+
+
+class B
+{
+    public static void main(String[] args) {
+        A a = null;
+        a.foo<error descr="Ambiguous method call: both 'A.foo(Collection<?>)' and 'A.foo(List<?>)' match">(null)</error>;
+    }
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/codeInsight/daemon/LightAdvHighlightingJdk7Test.java b/java/java-tests/testSrc/com/intellij/codeInsight/daemon/LightAdvHighlightingJdk7Test.java
index 9571dea1aec0..c80cd989778c 100644
--- a/java/java-tests/testSrc/com/intellij/codeInsight/daemon/LightAdvHighlightingJdk7Test.java
+++ b/java/java-tests/testSrc/com/intellij/codeInsight/daemon/LightAdvHighlightingJdk7Test.java
@@ -170,6 +170,7 @@ public class LightAdvHighlightingJdk7Test extends LightDaemonAnalyzerTestCase {
   public void testWrongArgsAndUnknownTypeParams() { doTest(false, false); }
   public void testAmbiguousMethodCallIDEA97983() { doTest(false, false); }
   public void testAmbiguousMethodCallIDEA100314() { doTest(false, false); }
+  public void testAmbiguousMethodCallIDEA67668() { doTest(false, false); }
   public void testInstanceMemberNotAccessibleInStaticContext() { doTest(false, false); }
   public void testRejectedTypeParamsForConstructor() { doTest(false, false); }
   public void testAnnotationArgs() throws Exception { doTest(false, false);}