Shorten References: Compare resolved calls when shortening receiver of qualified call expression

#KT-13660 Fixed

idea/idea-core/src/org/jetbrains/kotlin/idea/core/ShortenReferences.kt

@@ -37,6 +37,7 @@ import org.jetbrains.kotlin.renderer.DescriptorRenderer
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.calls.callUtil.getCalleeExpressionIfAny
 import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
+import org.jetbrains.kotlin.resolve.calls.model.VariableAsFunctionResolvedCall
 import org.jetbrains.kotlin.resolve.calls.tasks.ExplicitReceiverKind
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
 import org.jetbrains.kotlin.resolve.scopes.receivers.ImplicitReceiver
@@ -428,13 +429,17 @@ class ShortenReferences(val options: (KtElement) -> Options = { Options.DEFAULT
             val selector = element.selectorExpression ?: return Skip
             val callee = selector.getCalleeExpressionIfAny() as? KtReferenceExpression ?: return Skip
             val targets = callee.targets(bindingContext)
+            val varAsFunResolvedCall = callee.getResolvedCall(bindingContext) as? VariableAsFunctionResolvedCall
             if (targets.isEmpty()) return Skip
 
             val scope = element.getResolutionScope(bindingContext, resolutionFacade)
             val selectorCopy = selector.copy() as KtReferenceExpression
             val newContext = selectorCopy.analyzeInContext(scope, selector)
-            val targetsWhenShort = (selectorCopy.getCalleeExpressionIfAny() as KtReferenceExpression).targets(newContext)
+            val newCallee = selectorCopy.getCalleeExpressionIfAny() as KtReferenceExpression
+            val targetsWhenShort = newCallee.targets(newContext)
+            val varAsFunResolvedCallWhenShort = newCallee.getResolvedCall(newContext) as? VariableAsFunctionResolvedCall
             val targetsMatch = targetsMatch(targets, targetsWhenShort)
+                               && (varAsFunResolvedCall == null || resolvedCallsMatch(varAsFunResolvedCall, varAsFunResolvedCallWhenShort))
 
             if (receiver is KtThisExpression) {
                 if (!targetsMatch) return Skip
@@ -471,6 +476,11 @@ class ShortenReferences(val options: (KtElement) -> Options = { Options.DEFAULT
             }
         }
 
+        private fun resolvedCallsMatch(rc1: VariableAsFunctionResolvedCall?, rc2: VariableAsFunctionResolvedCall?): Boolean {
+            return rc1?.variableCall?.candidateDescriptor?.asString() == rc2?.variableCall?.candidateDescriptor?.asString() &&
+                   rc1?.functionCall?.candidateDescriptor?.asString() == rc2?.functionCall?.candidateDescriptor?.asString()
+        }
+
         override fun shortenElement(element: KtDotQualifiedExpression): KtElement {
             return element.replace(element.selectorExpression!!) as KtElement
         }

idea/testData/shortenRefs/extensionFunctionVarInvokedWithQualifier.kt

@@ -0,0 +1,7 @@
+object X{ }
+
+<selection>class Y {
+    fun f(op: X.()->Unit) {
+        X.op()
+    }
+}</selection>

idea/testData/shortenRefs/extensionFunctionVarInvokedWithQualifier.kt.after

@@ -0,0 +1,7 @@
+object X{ }
+
+class Y {
+    fun f(op: X.()->Unit) {
+        X.op()
+    }
+}

idea/tests/org/jetbrains/kotlin/shortenRefs/ShortenRefsTestGenerated.java

@@ -59,6 +59,12 @@ public class ShortenRefsTestGenerated extends AbstractShortenRefsTest {
         doTest(fileName);
     }
 
+    @TestMetadata("extensionFunctionVarInvokedWithQualifier.kt")
+    public void testExtensionFunctionVarInvokedWithQualifier() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("idea/testData/shortenRefs/extensionFunctionVarInvokedWithQualifier.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("InterfaceInExpression.kt")
     public void testInterfaceInExpression() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("idea/testData/shortenRefs/InterfaceInExpression.kt");