add single static import: ensure not available when conflict(IDEA-174983)

when methods (> 1) with same name exist in the containing class

java/java-impl/src/com/intellij/codeInsight/intention/impl/AddSingleMemberStaticImportAction.java

@@ -104,6 +104,9 @@ public class AddSingleMemberStaticImportAction extends BaseElementAtCaretIntenti
                     else return null;
                   }
                 }
+                else if (method == null && call.getMethodExpression().multiResolve(false).length > 0) {
+                  return null;
+                }
               }
               else {
                 final PsiJavaCodeReferenceElement copy = (PsiJavaCodeReferenceElement)refExpr.copy();

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/addSingleStaticImport/ConflictingNamesInScope.java

@@ -0,0 +1,9 @@
+import foo.*;
+class MyTest {
+  {
+    Assert.assert<caret>True(false);
+  }
+  
+  static void assertTrue() {}
+  static void assertTrue(String message, boolean flag) {}
+}

java/java-tests/testSrc/com/intellij/java/codeInsight/intention/AddSingleStaticImportActionTest.java

@@ -131,6 +131,13 @@ public class AddSingleStaticImportActionTest extends JavaCodeInsightFixtureTestC
     }
   }
 
+  public void testConflictingNamesInScope() throws Exception {
+    myFixture.addClass("package foo; public class Assert {public static void assertTrue(boolean b) {}}");
+    myFixture.configureByFile(getTestName(false) + ".java");
+    IntentionAction intention = myFixture.getAvailableIntention("Add static import for 'foo.Assert.assertTrue'");
+    assertNull(intention);
+  }
+
   public void testProhibitWhenMethodWithIdenticalSignatureAlreadyImportedFromAnotherClass() throws Exception {
     myFixture.addClass("package foo; class Foo {public static void foo(int i){}}");
     myFixture.addClass("package foo; class Bar {public static void foo(int i){}}");