X-Git-Url: http://nitlanguage.org

diff --git a/src/model/model.nit b/src/model/model.nit
index 3841daf..b9d6aa2 100644
--- a/src/model/model.nit
+++ b/src/model/model.nit
@@ -300,18 +300,15 @@ redef class MModule
 		var props = self.model.get_mproperties_by_name(name)
 		if props == null then return null
 		var res: nullable MMethod = null
+		var recvtype = recv.intro.bound_mtype
 		for mprop in props do
 			assert mprop isa MMethod
-			var intro = mprop.intro_mclassdef
-			for mclassdef in recv.mclassdefs do
-				if not self.in_importation.greaters.has(mclassdef.mmodule) then continue
-				if not mclassdef.in_hierarchy.greaters.has(intro) then continue
-				if res == null then
-					res = mprop
-				else if res != mprop then
-					print("Fatal Error: ambigous property name '{name}'; conflict between {mprop.full_name} and {res.full_name}")
-					abort
-				end
+			if not recvtype.has_mproperty(self, mprop) then continue
+			if res == null then
+				res = mprop
+			else if res != mprop then
+				print("Fatal Error: ambigous property name '{name}'; conflict between {mprop.full_name} and {res.full_name}")
+				abort
 			end
 		end
 		return res
@@ -809,19 +806,19 @@ abstract class MType
 		end
 		#print "4.is {sub} a {sup}? <- no more resolution"
 
-		assert sub isa MClassType else print "{sub} <? {sub}" # It is the only remaining type
-
-		# A unfixed formal type can only accept itself
-		if sup isa MFormalType then
-			return false
+		if sub isa MBottomType then
+			return true
 		end
 
-		if sup isa MNullType then
-			# `sup` accepts only null
+		assert sub isa MClassType else print "{sub} <? {sub}" # It is the only remaining type
+
+		# Handle sup-type when the sub-type is class-based (other cases must have be identified before).
+		if sup isa MFormalType or sup isa MNullType or sup isa MBottomType then
+			# These types are not super-types of Class-based types.
 			return false
 		end
 
-		assert sup isa MClassType # It is the only remaining type
+		assert sup isa MClassType else print "got {sup} {sub.inspect}" # It is the only remaining type
 
 		# Now both are MClassType, we need to dig
 
@@ -1010,7 +1007,7 @@ abstract class MType
 	# The result is returned exactly as declared in the "type" property (verbatim).
 	# So it could be another formal type.
 	#
-	# In case of conflict, the method aborts.
+	# In case of conflicts or inconsistencies in the model, the method returns a `MBottomType`.
 	fun lookup_bound(mmodule: MModule, resolved_receiver: MType): MType do return self
 
 	# Resolve the formal type to its simplest equivalent form.
@@ -1024,6 +1021,8 @@ abstract class MType
 	#
 	# By default, return self.
 	# See the redefinitions for specific behavior in each kind of type.
+	#
+	# In case of conflicts or inconsistencies in the model, the method returns a `MBottomType`.
 	fun lookup_fixed(mmodule: MModule, resolved_receiver: MType): MType do return self
 
 	# Can the type be resolved?
@@ -1365,7 +1364,7 @@ class MVirtualType
 
 	redef fun lookup_bound(mmodule: MModule, resolved_receiver: MType): MType
 	do
-		return lookup_single_definition(mmodule, resolved_receiver).bound.as(not null)
+		return lookup_single_definition(mmodule, resolved_receiver).bound or else new MBottomType(model)
 	end
 
 	private fun lookup_single_definition(mmodule: MModule, resolved_receiver: MType): MVirtualTypeDef
@@ -1400,7 +1399,8 @@ class MVirtualType
 		assert resolved_receiver isa MClassType # It is the only remaining type
 
 		var prop = lookup_single_definition(mmodule, resolved_receiver)
-		var res = prop.bound.as(not null)
+		var res = prop.bound
+		if res == null then return new MBottomType(model)
 
 		# Recursively lookup the fixed result
 		res = res.lookup_fixed(mmodule, resolved_receiver)
@@ -1815,16 +1815,26 @@ class MSignature
 		for i in [0..mparameters.length[ do
 			var parameter = mparameters[i]
 			if parameter.is_vararg then
-				assert vararg_rank == -1
+				if vararg_rank >= 0 then
+					# If there is more than one vararg,
+					# consider that additional arguments cannot be mapped.
+					vararg_rank = -1
+					break
+				end
 				vararg_rank = i
 			end
 		end
 		self.vararg_rank = vararg_rank
 	end
 
-	# The rank of the ellipsis (`...`) for vararg (starting from 0).
+	# The rank of the main ellipsis (`...`) for vararg (starting from 0).
 	# value is -1 if there is no vararg.
 	# Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
+	#
+	# From a model POV, a signature can contain more than one vararg parameter,
+	# the `vararg_rank` just indicates the one that will receive the additional arguments.
+	# However, currently, if there is more that one vararg parameter, no one will be the main one,
+	# and additional arguments will be refused.
 	var vararg_rank: Int is noinit
 
 	# The number of parameters