fixes IntSet copy!(a,a) for a === a; #14581

(cherry picked from commit 166f484) ref #14582
JuliaLang · Jan 9, 2016 · 93ccda0 · 93ccda0
1 parent 4cd00d1
commit 93ccda0
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Showing 2 changed files with 8 additions and 2 deletions.
diff --git a/base/intset.jl b/base/intset.jl
@@ -157,8 +157,12 @@ function symdiff!(s::IntSet, ns)
 end
 
 function copy!(to::IntSet, from::IntSet)
-    empty!(to)
-    union!(to, from)
+    if is(to, from)
+        return to
+    else
+        empty!(to)
+        return union!(to, from)
+    end
 end
 
 function in(n::Integer, s::IntSet)

diff --git a/test/intset.jl b/test/intset.jl
@@ -86,6 +86,8 @@ k = IntSet([4, 5])
 copy!(k, i)
 @test k == i
 @test !(k === i)
+copy!(k, k)
+@test k == i
 
 # unions
 i = IntSet([1, 2, 3])