From c1bfc9f2a7e8d49bdc3644ee233d9d03e299a542 Mon Sep 17 00:00:00 2001
From: Louis-Vincent Boudreault <lv.boudreault95@gmail.com>
Date: Sun, 10 Nov 2019 10:31:15 -0500
Subject: [PATCH] Fixed safe-call miss cast when reference primitive data
 types

Signed-off-by: Louis-Vincent Boudreault <lv.boudreault95@gmail.com>
---
 src/compiler/abstract_compiler.nit |   20 ++++++++++--
 tests/base_safe2.nit               |   63 ++++++++++++++++++++++++++++++++++++
 tests/sav/base_safe2.res           |    5 +++
 tests/sav/base_safe2_alt1.res      |    1 +
 4 files changed, 87 insertions(+), 2 deletions(-)
 create mode 100644 tests/base_safe2.nit
 create mode 100644 tests/sav/base_safe2.res
 create mode 100644 tests/sav/base_safe2_alt1.res

diff --git a/src/compiler/abstract_compiler.nit b/src/compiler/abstract_compiler.nit
index 77a20f4..57e738f 100644
--- a/src/compiler/abstract_compiler.nit
+++ b/src/compiler/abstract_compiler.nit
@@ -4390,9 +4390,25 @@ redef class ASendExpr
 		var res = v.compile_callsite(callsite, args)
 		if is_safe then
 			if res != null then
-				var orig_res = res
+				# `callsite.mpropdef` may reference a method whose
+				# return type is a primitive type in C. If it is
+				# the case, we must convert the primitive type to
+				# a `val*` to support nullable assignment.
+				# Autobox's job is to convert primitive type to
+				# nullable type, eg from `Int` to `nullable `Int`.
+				# The target type reside in `self.mtype`.
+				var original_res = v.autobox(res, self.mtype.as(not null))
+
+				# Here we must create a new_var in case the original
+				# type is not nullable. We can't call `autobox` to
+				# convert a complex type to its nullable version.
+				# eg if we have a type `A`, calling autobox like
+				# `autobox(A, nullable A)` will return `A` since
+				# `A` and `nullable A` have the same primitive
+				# type. The nullable qualifier is only used at
+				# compile time to add appropriate null checks.
 				res = v.new_var(self.mtype.as(not null))
-				v.add("{res} = {orig_res};")
+				v.add("{res} = {original_res};")
 				v.add("\} else \{")
 				v.add("{res} = NULL;")
 			end
diff --git a/tests/base_safe2.nit b/tests/base_safe2.nit
new file mode 100644
index 0000000..2c058df
--- /dev/null
+++ b/tests/base_safe2.nit
@@ -0,0 +1,63 @@
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+redef class Int
+	fun foo do print self
+end
+
+class A
+	var x: Int
+end
+
+class B
+	var a: nullable A = null
+end
+
+class C
+	var x: Int
+	var c: nullable C = null
+end
+
+class D
+	var x: nullable Int
+	var d: nullable D = null
+end
+
+var b = new B
+
+#alt1#b.a?.x.foo
+
+var a = new A(10)
+
+b.a = a
+print "b.a.x: {b.a?.x or else "nothing"}"
+
+var c1 = new C(1)
+var c2 = new C(10)
+var c3 = new C(100)
+c1.c = c2
+c2.c = c3
+
+print c1.c?.c?.x or else "null"
+print c1.c?.c?.c or else "null"
+
+var d1 = new D(1)
+var d2 = new D(10)
+var d3 = new D(null)
+
+d1.d = d2
+d2.d = d3
+
+print d1.d?.x or else "null"
+print d1.d?.d?.x or else "null"
diff --git a/tests/sav/base_safe2.res b/tests/sav/base_safe2.res
new file mode 100644
index 0000000..1ed892a
--- /dev/null
+++ b/tests/sav/base_safe2.res
@@ -0,0 +1,5 @@
+b.a.x: 10
+100
+null
+10
+null
diff --git a/tests/sav/base_safe2_alt1.res b/tests/sav/base_safe2_alt1.res
new file mode 100644
index 0000000..f48c476
--- /dev/null
+++ b/tests/sav/base_safe2_alt1.res
@@ -0,0 +1 @@
+Runtime error: Receiver is null (alt/base_safe2_alt1.nit:39)
-- 
1.7.9.5