Correctly generate drop glue for `Box<str>`

This fixes an ICE.  Closes issue #17734

diff --git a/src/librustc/middle/trans/glue.rs b/src/librustc/middle/trans/glue.rs
index 33a46c0ba36af729bf352683754d9034b7c53158..87bd451939eabc57d25bf58334b00f7c93ed8709 100644 (file)
--- a/src/librustc/middle/trans/glue.rs
+++ b/src/librustc/middle/trans/glue.rs
@@ -429,7 +429,7 @@ fn make_drop_glue<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, v0: ValueRef, t: ty::t)
                     tvec::make_drop_glue_unboxed(bcx, v0, ty, true)
                 }
                 ty::ty_str => {
-                    let unit_ty = ty::sequence_element_type(bcx.tcx(), t);
+                    let unit_ty = ty::sequence_element_type(bcx.tcx(), content_ty);
                     tvec::make_drop_glue_unboxed(bcx, v0, unit_ty, true)
                 }
                 ty::ty_trait(..) => {