[name hints] show hints when resolve returns multiple overloaded methods, for parameter names which are the same

java/java-impl/src/com/intellij/codeInsight/hints/JavaHintUtils.kt

@@ -17,17 +17,46 @@ package com.intellij.codeInsight.hints
 
 import com.intellij.codeInsight.hints.settings.ParameterNameHintsSettings
 import com.intellij.psi.*
+import com.intellij.psi.impl.source.tree.java.PsiMethodCallExpressionImpl
+import com.intellij.psi.impl.source.tree.java.PsiNewExpressionImpl
 import com.intellij.psi.util.TypeConversionUtil
 
 
 object JavaInlayHintsProvider {
 
+  
   fun createHints(callExpression: PsiCallExpression): Set<InlayInfo> {
-    val (element, substitutor) = callExpression.resolveMethodGenerics().let { it.element to it.substitutor }
+    val resolveResult = callExpression.resolveMethodGenerics()
+    val hints = createHintsForResolvedMethod(callExpression, resolveResult)
+    if (hints.isNotEmpty()) return hints
+    
+    return when (callExpression) {
+      is PsiMethodCallExpressionImpl -> createMergedHints(callExpression, callExpression.methodExpression.multiResolve(false))
+      is PsiNewExpressionImpl -> createMergedHints(callExpression, callExpression.constructorFakeReference.multiResolve(false))
+      else -> emptySet()
+    }
+  }
+
+  private fun createMergedHints(callExpression: PsiCallExpression, 
+                                results: Array<out ResolveResult>): Set<InlayInfo> {
+    val resultSet = results
+      .filter { it.element != null }
+      .map { createHintsForResolvedMethod(callExpression, it) }
+      
+    if (resultSet.isEmpty() || resultSet.any { it.isEmpty() }) return emptySet()
+    
+    return resultSet.reduce { left, right -> left.intersect(right) }
+  }
+
+  private fun createHintsForResolvedMethod(callExpression: PsiCallExpression, resolveResult: ResolveResult): Set<InlayInfo> {
+    val element = resolveResult.element
+    val substitutor = (resolveResult as? JavaResolveResult)?.substitutor ?: PsiSubstitutor.EMPTY
+    
     if (element is PsiMethod && isMethodToShow(element, callExpression)) {
       val info = getCallInfo(callExpression, element)
       return createHintSet(info, substitutor)
     }
+    
     return emptySet()
   }
 

java/java-psi-impl/src/com/intellij/psi/impl/source/tree/java/PsiNewExpressionImpl.java

@@ -134,7 +134,7 @@ public class PsiNewExpressionImpl extends ExpressionPsiElement implements PsiNew
     return resolveConstructor();
   }
 
-  private PsiPolyVariantCachingReference getConstructorFakeReference() {
+  public PsiPolyVariantCachingReference getConstructorFakeReference() {
     return new PsiPolyVariantCachingReference() {
       @Override
       @NotNull

java/java-tests/testSrc/com/intellij/codeInsight/daemon/inlays/JavaParameterNameHintsTest.kt

@@ -844,4 +844,35 @@ class Test {
     onLineStartingWith("test").assertInlays("parent->c", "child->d", "vx->v", "vy->v")
   }
 
+  fun `test show ambigous`() {
+    setup("""
+class Test {
+  void main() {
+    test(10, x);
+  }
+  void test(int a, String bS) {}
+  void test(int a, int bI) {}
+}
+""")
+    
+    onLineStartingWith("test").assertInlays("a->10")
+  }
+
+  fun `test show ambigous constructor`() {
+    setup("""
+class Test {
+  void main() {
+    new X(10, x);
+  }
+}
+
+class X {
+  X(int a, int bI) {}
+  X(int a, String bS) {}
+}
+""")
+    
+    onLineStartingWith("new").assertInlays("a->10")
+  }
+
 }

platform/lang-impl/src/com/intellij/codeInsight/hints/ParameterHintsPassFactory.java

@@ -116,7 +116,7 @@ public class ParameterHintsPassFactory extends AbstractProjectComponent implemen
       List<InlayInfo> hints = provider.getParameterHints(element);
       if (hints.isEmpty()) return;
       MethodInfo info = provider.getMethodInfo(element);
-      if (info != null && !isMatchedByAny(info, blackListMatchers)) {
+      if (info == null || !isMatchedByAny(info, blackListMatchers)) {
         hints.forEach((h) -> myAnnotations.put(h.getOffset(), h.getText()));  
       }
     }