diff --git a/base/inference.jl b/base/inference.jl
index fd45eefcf0d1d..c487302bdce4e 100644
--- a/base/inference.jl
+++ b/base/inference.jl
@@ -1858,7 +1858,7 @@ function without_linenums(a::Array{Any,1})
     l
 end
 
-const _pure_builtins = {tuple, tupleref, tuplelen, fieldtype, apply_type, is, isa, typeof} # known affect-free calls (also effect-free)
+const _pure_builtins = {tuple, tupleref, tuplelen, fieldtype, apply_type, is, isa, typeof, typeassert} # known affect-free calls (also effect-free)
 const _pure_builtins_volatile = {getfield, arrayref} # known effect-free calls (might not be affect-free)
 
 function is_pure_builtin(f)
@@ -2039,12 +2039,13 @@ function inlineable(f, e::Expr, atypes, sv, enclosing_ast)
     #     end
     # end
 
-    # when 1 method matches the inferred types, there is still a chance
-    # of a no-method error at run time, unless the inferred types are a
-    # subset of the method signature.
-    if !(atypes <: meth[1])
-        return NF
+    # Undef is a bad type
+    for ty in atypes
+        if Undef <: ty
+            return NF
+        end
     end
+
     if !isa(linfo,LambdaStaticData) || meth[3].func.env !== ()
         return NF
     end
@@ -2093,6 +2094,7 @@ function inlineable(f, e::Expr, atypes, sv, enclosing_ast)
     args = f_argnames(ast)
     na = length(args)
 
+    isva = false
     if na>0 && is_rest_arg(ast.args[1][na])
         vaname = args[na]
         len_argexprs = length(argexprs)
@@ -2127,6 +2129,7 @@ function inlineable(f, e::Expr, atypes, sv, enclosing_ast)
             # construct tuple-forming expression for argument tail
             vararg = mk_tuplecall(argexprs[na:end])
             argexprs = {argexprs[1:(na-1)]..., vararg}
+            isva = true
         end
     end
     @assert na == length(argexprs)
@@ -2163,10 +2166,47 @@ function inlineable(f, e::Expr, atypes, sv, enclosing_ast)
     # see if each argument occurs only once in the body expression
     stmts = {}
     stmts_free = true # true = all entries of stmts are effect_free
-    for i=length(args):-1:1 # stmts_free needs to be calculated in reverse-argument order
+
+    methargs = meth[1]
+    nm = length(methargs)
+    for i=na:-1:1 # stmts_free needs to be calculated in reverse-argument order
         a = args[i]
         aei = argexprs[i]
-        aeitype = exprtype(aei)
+        aeitype = argtype = typeintersect(exprtype(aei),Any)  # remove Undef
+        if aeitype == ANY
+            aeitype = Any
+        end
+        if isva
+            if nm == 0
+                methitype = ()
+            elseif i > nm
+                methitype = methargs[end]
+                if isvarargtype(methitype)
+                    methitype = (methitype,)
+                else
+                    methitype = ()
+                end
+            else
+                methitype = tuple(methargs[i:end]...)
+            end
+            isva = false
+        else
+            if i < nm
+                methitype = methargs[i]
+            else
+                methitype = methargs[end]
+                if isvarargtype(methitype)
+                    methitype = (methitype::Vararg).parameters[1]
+                else
+                    @assert i==nm
+                end
+            end
+        end
+        needtypeassert = false
+        if !(aeitype <: methitype)
+            needtypeassert = true
+            aeitype = methitype
+        end
 
         islocal = false # if the argument name is also used as a local variable,
                         # we need to keep it as a variable name
@@ -2185,7 +2225,7 @@ function inlineable(f, e::Expr, atypes, sv, enclosing_ast)
         # ok for argument to occur more than once if the actual argument
         # is a symbol or constant, or is not affected by previous statements
         # that will exist after the inlining pass finishes
-        affect_free = stmts_free && !islocal # false = previous statements might affect the result of evaluating argument
+        affect_free = stmts_free && !islocal && !needtypeassert # false = previous statements might affect the result of evaluating argument
         occ = 0
         for j = length(body.args):-1:1
             b = body.args[j]
@@ -2201,14 +2241,21 @@ function inlineable(f, e::Expr, atypes, sv, enclosing_ast)
             end
         end
         free = effect_free(aei,sv,true)
-        if ((occ==0 && is(aeitype,None)) || islocal || (occ > 1 && !inline_worthy(aei, occ)) ||
-            (affect_free && !free) || (!affect_free && !effect_free(aei,sv,false)))
-            if occ != 0 # islocal=true is implied
+        if ((occ==0 && is(aeitype,None)) || islocal || needtypeassert || (occ > 1 && !inline_worthy(aei, occ)) ||
+                (affect_free && !free) || (!affect_free && !effect_free(aei,sv,false)))
+            if occ != 0 || needtypeassert # islocal=true is implied
                 # introduce variable for this argument
                 vnew = unique_name(enclosing_ast, ast)
                 add_variable(enclosing_ast, vnew, aeitype, !islocal)
-                unshift!(stmts, Expr(:(=), vnew, aei))
                 argexprs[i] = aeitype===Any ? vnew : SymbolNode(vnew,aeitype)
+                if needtypeassert
+                    vnew2 = unique_name(enclosing_ast, ast)
+                    add_variable(enclosing_ast, vnew2, argtype, true)
+                    push!(stmts, Expr(:(=), vnew, Expr(:call, TopNode(:typeassert), vnew2, aeitype)))
+                else
+                    vnew2 = vnew
+                end
+                unshift!(stmts, Expr(:(=), vnew2, aei))
                 stmts_free &= free
             elseif !free && !isType(aeitype)
                 unshift!(stmts, aei)