avoid forming Tuple{Union(), ...}, which was confusing codegen.

see comment in #11100 ideally, any Tuple containing Union() should collapse to Union(), but I will just put a bandaid on this for now.
JuliaLang · May 26, 2015 · 4d9bc85 · 4d9bc85 · tkelman · May 27, 2015
1 parent adf2624
commit 4d9bc85
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/base/inference.jl b/base/inference.jl
@@ -619,10 +619,12 @@ function abstract_call_gf(f, fargs, argtype, e)
             return getfield_tfunc(fargs, argtypes[1], argtypes[2])[1]
         elseif istopfunction(tm, f, :next)
             isa(e,Expr) && (e.head = :call1)
-            return Tuple{getfield_tfunc(fargs, argtypes[1], argtypes[2])[1], Int}
+            t1 = getfield_tfunc(fargs, argtypes[1], argtypes[2])[1]
+            return t1===Bottom ? Bottom : Tuple{t1, Int}
         elseif istopfunction(tm, f, :indexed_next)
             isa(e,Expr) && (e.head = :call1)
-            return Tuple{getfield_tfunc(fargs, argtypes[1], argtypes[2])[1], Int}
+            t1 = getfield_tfunc(fargs, argtypes[1], argtypes[2])[1]
+            return t1===Bottom ? Bottom : Tuple{t1, Int}
         end
     end
     if istopfunction(tm, f, :promote_type) || istopfunction(tm, f, :typejoin)