Fixes infinite recursion bug for immediate nullable self types

2 files changed, 61 insertions, 2 deletions

diff --git a/core/src/main/kotlin/links/DRI.kt b/core/src/main/kotlin/links/DRI.kt
index c13eb04c..b7e5dd1c 100644
--- a/core/src/main/kotlin/links/DRI.kt
+++ b/core/src/main/kotlin/links/DRI.kt
@@ -72,7 +72,7 @@ sealed class TypeReference {
     companion object {
         fun from(d: ReceiverParameterDescriptor): TypeReference? =
             when (d.value) {
-                is ExtensionReceiver -> from(d.type)
+                is ExtensionReceiver -> fromPossiblyNullable(d.type)
                 else -> run {
                     println("Unknown value type for $d")
                     null
@@ -80,7 +80,7 @@ sealed class TypeReference {
             }
 
         fun from(d: ValueParameterDescriptor): TypeReference? =
-            from(d.type)
+            fromPossiblyNullable(d.type)
 
         private fun fromPossiblyNullable(t: KotlinType, self: KotlinType? = null): TypeReference =
             from(t, self).let { if (t.isMarkedNullable) Nullable(it) else it }
diff --git a/core/src/test/kotlin/basic/DRITest.kt b/core/src/test/kotlin/basic/DRITest.kt
index f8328e35..93a874ef 100644
--- a/core/src/test/kotlin/basic/DRITest.kt
+++ b/core/src/test/kotlin/basic/DRITest.kt
@@ -40,4 +40,63 @@ class DRITest: AbstractCoreTest() {
         }
     }
 
+    @Test
+    fun `#634 with immediate nullable self`() {
+        val configuration = dokkaConfiguration {
+            passes {
+                pass {
+                    sourceRoots = listOf("src/")
+                }
+            }
+        }
+
+        testInline(
+            """
+            |/src/main/kotlin/basic/Test.kt
+            |package toplevel
+            |
+            |fun <T : Comparable<T>> Array<T>.doSomething(t: T?): Array<T> = TODO()
+            |}
+        """.trimMargin(),
+            configuration
+        ) {
+            documentablesMergingStage = { module ->
+                val expected = Nullable(TypeParam(listOf(TypeConstructor("kotlin.Comparable", listOf(SelfType)))))
+                val actual = module.packages.single()
+                    .functions.single()
+                    .dri.callable?.params?.single()
+                assertEquals(expected, actual)
+            }
+        }
+    }
+
+    @Test
+    fun `#634 with generic nullable receiver`() {
+        val configuration = dokkaConfiguration {
+            passes {
+                pass {
+                    sourceRoots = listOf("src/")
+                }
+            }
+        }
+
+        testInline(
+            """
+            |/src/main/kotlin/basic/Test.kt
+            |package toplevel
+            |
+            |fun <T : Comparable<T>> T?.doSomethingWithNullable() = TODO()
+            |}
+        """.trimMargin(),
+            configuration
+        ) {
+            documentablesMergingStage = { module ->
+                val expected = Nullable(TypeParam(listOf(TypeConstructor("kotlin.Comparable", listOf(SelfType)))))
+                val actual = module.packages.single()
+                    .functions.single()
+                    .dri.callable?.receiver
+                assertEquals(expected, actual)
+            }
+        }
+    }
 }
\ No newline at end of file