Finally fixed KT-8751

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/ExpectedInfos.kt

@@ -266,8 +266,8 @@ class ExpectedInfos(
 
             //TODO: we can loose partially inferred substitution here but what to do?
             if (parameter.type.containsError()) {
-                parameter = parameter.original
                 descriptor = descriptor.original
+                parameter = descriptor.valueParameters[parameter.index]
                 argumentToParameter = call.mapArgumentsToParameters(descriptor)
             }
 

idea/idea-completion/testData/smartMultiFile/KT_8751_2/JavaClass.java

@@ -0,0 +1,6 @@
+class L<T> {}
+
+class JavaClass {
+    <T> void foo(L<T> l) {}
+}
+

idea/idea-completion/testData/smartMultiFile/KT_8751_2/KT_8751_2.kt

@@ -0,0 +1,8 @@
+class KotlinClass : JavaClass(){
+}
+
+fun foo(c: KotlinClass, l: L<String>) {
+    c.foo(<caret>)
+}
+
+// EXIST: l

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/MultiFileSmartCompletionTestGenerated.java

@@ -107,6 +107,12 @@ public class MultiFileSmartCompletionTestGenerated extends AbstractMultiFileSmar
         doTest(fileName);
     }
 
+    @TestMetadata("KT_8751_2")
+    public void testKT_8751_2() throws Exception {
+        String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/smartMultiFile/KT_8751_2/");
+        doTest(fileName);
+    }
+
     @TestMetadata("NoObjectDuplication")
     public void testNoObjectDuplication() throws Exception {
         String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/smartMultiFile/NoObjectDuplication/");