completion: take into account provided type arguments (IDEA-169478)

java/java-impl/src/com/intellij/codeInsight/ExpectedTypesProvider.java

@@ -985,8 +985,8 @@ public class ExpectedTypesProvider {
         PsiSubstitutor substitutor;
         if (candidateInfo instanceof MethodCandidateInfo) {
           final MethodCandidateInfo info = (MethodCandidateInfo)candidateInfo;
-          substitutor = MethodCandidateInfo.ourOverloadGuard
-            .doPreventingRecursion(argumentList, false, () -> info.inferTypeArguments(policy, args, true));
+          substitutor = MethodCandidateInfo.ourOverloadGuard.doPreventingRecursion(argumentList, false,
+                                                                                   () -> info.inferSubstitutorFromArgs(policy, args));
           if (!info.isStaticsScopeCorrect() && !method.hasModifierProperty(PsiModifier.STATIC)) continue;
         }
         else {
@@ -999,8 +999,7 @@ public class ExpectedTypesProvider {
 
         if (leftArgs != null && candidateInfo instanceof MethodCandidateInfo) {
           substitutor = MethodCandidateInfo.ourOverloadGuard.doPreventingRecursion(argumentList, false,
-                                                                                   () -> ((MethodCandidateInfo)candidateInfo)
-                                                                                     .inferTypeArguments(policy, leftArgs, true));
+                                                                                   () -> ((MethodCandidateInfo)candidateInfo).inferSubstitutorFromArgs(policy, leftArgs));
           if (substitutor != null) {
             inferMethodCallArgumentTypes(argument, forCompletion, leftArgs, index, method, substitutor, array);
           }

java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionUtil.java

@@ -806,7 +806,8 @@ public class JavaCompletionUtil {
         PsiElement composite = leaf == null ? null : leaf.getParent();
         if (composite instanceof PsiMethodReferenceExpression && LambdaHighlightingUtil.insertSemicolon(composite.getParent())) {
           insertAdditionalSemicolon = false;
-        } else if (composite instanceof PsiReferenceExpression) {
+        }
+        else if (composite instanceof PsiReferenceExpression) {
           PsiElement parent = composite.getParent();
           if (parent instanceof PsiMethodCallExpression) {
             parent = parent.getParent();
@@ -814,6 +815,9 @@ public class JavaCompletionUtil {
           if (parent instanceof PsiLambdaExpression && !LambdaHighlightingUtil.insertSemicolonAfter((PsiLambdaExpression)parent)) {
             insertAdditionalSemicolon = false;
           }
+          if (parent instanceof PsiMethodReferenceExpression && LambdaHighlightingUtil.insertSemicolon(parent.getParent())) {
+            insertAdditionalSemicolon = false;
+          }
         }
         if (insertAdditionalSemicolon) {
           toInsert = TailType.SEMICOLON;

java/java-tests/testData/codeInsight/completion/smartType/StaticMethodReferenceInContextWithTypeArgs-out.java

@@ -0,0 +1,12 @@
+
+import java.util.function.Consumer;
+
+class Test {
+  private static <T> void _f(Consumer<T> c) {}
+
+  private static void bar(final String s) {}
+
+  public static void main(String[] argArr) {
+    Test.<String>_f(Test::bar);
+  }
+}

java/java-tests/testData/codeInsight/completion/smartType/StaticMethodReferenceInContextWithTypeArgs.java

@@ -0,0 +1,12 @@
+
+import java.util.function.Consumer;
+
+class Test {
+  private static <T> void _f(Consumer<T> c) {}
+
+  private static void bar(final String s) {}
+
+  public static void main(String[] argArr) {
+    Test.<String>_f(b<caret>);
+  }
+}

java/java-tests/testSrc/com/intellij/codeInsight/completion/SmartType18CompletionTest.java

@@ -156,6 +156,10 @@ public class SmartType18CompletionTest extends LightFixtureCompletionTestCase {
   }
 
   public void testStaticMethodReference() { doTest(false); }
+  public void testStaticMethodReferenceInContextWithTypeArgs() {
+    configureByTestName();
+    checkResultByFile("/" + getTestName(false) + "-out.java");
+  }
 
   public void testOuterMethodReference() { doTest(true); }
   public void testNoAnonymousOuterMethodReference() { doAntiTest(); }