Merge pull request #4976 from ErinaceusEuropaeus/fix_zip_save

Fix std.range.Zip.save

std/range/package.d

@@ -3903,7 +3903,7 @@ struct Zip(Ranges...)
         @property Zip save()
         {
             //Zip(ranges[0].save, ranges[1].save, ..., stoppingPolicy)
-            return mixin (q{Zip(%(ranges[%s]%|, %), stoppingPolicy)}.format(iota(0, R.length)));
+            return mixin (q{Zip(%(ranges[%s].save%|, %), stoppingPolicy)}.format(iota(0, R.length)));
         }
     }
 
@@ -4423,6 +4423,19 @@ pure unittest
     auto zz = z.save;
 }
 
+pure unittest
+{
+    import std.typecons : tuple;
+
+    auto r1 = [0,1,2];
+    auto r2 = [1,2,3];
+    auto z1 = zip(refRange(&r1), refRange(&r2));
+    auto z2 = z1.save;
+    z1.popFront();
+    assert(z1.front == tuple(1,2));
+    assert(z2.front == tuple(0,1));
+}
+
 /*
     Generate lockstep's opApply function as a mixin string.
     If withIndex is true prepend a size_t index to the delegate.