From 70b9ad1748748d93ccef95b59435a7357b350d11 Mon Sep 17 00:00:00 2001
From: Niko Matsakis <niko@alum.mit.edu>
Date: Tue, 30 Apr 2013 14:09:14 -0400
Subject: [PATCH] rustc: work around issue with default-method-simple, fix some
 rebase errors

---
 src/librustc/middle/ty.rs                    |  7 +++++++
 src/librustc/middle/typeck/check/method.rs   | 16 ++++++++++++++++
 src/librustc/middle/typeck/check/mod.rs      |  3 ++-
 src/librustc/middle/typeck/check/regionck.rs | 10 ++++------
 4 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs
index 28705ac4932..b17dac82048 100644
--- a/src/librustc/middle/ty.rs
+++ b/src/librustc/middle/ty.rs
@@ -1553,6 +1553,13 @@ pub fn type_is_ty_var(ty: t) -> bool {
 
 pub fn type_is_bool(ty: t) -> bool { get(ty).sty == ty_bool }
 
+pub fn type_is_self(ty: t) -> bool {
+    match get(ty).sty {
+        ty_self(*) => true,
+        _ => false
+    }
+}
+
 pub fn type_is_structural(ty: t) -> bool {
     match get(ty).sty {
       ty_struct(*) | ty_tup(_) | ty_enum(*) | ty_closure(_) | ty_trait(*) |
diff --git a/src/librustc/middle/typeck/check/method.rs b/src/librustc/middle/typeck/check/method.rs
index 0cc2ddd32b4..de6530fb464 100644
--- a/src/librustc/middle/typeck/check/method.rs
+++ b/src/librustc/middle/typeck/check/method.rs
@@ -658,6 +658,12 @@ pub impl<'self> LookupContext<'self> {
 
         let tcx = self.tcx();
         return match ty::get(self_ty).sty {
+            ty::ty_rptr(_, self_mt) if default_method_hack(self_mt) => {
+                (self_ty,
+                 ty::AutoDerefRef(ty::AutoDerefRef {
+                     autoderefs: autoderefs,
+                     autoref: None}))
+            }
             ty::ty_rptr(_, self_mt) => {
                 let region = self.infcx().next_region_var_nb(self.expr.span);
                 (ty::mk_rptr(tcx, region, self_mt),
@@ -679,6 +685,16 @@ pub impl<'self> LookupContext<'self> {
                      autoref: None}))
             }
         };
+
+        fn default_method_hack(self_mt: ty::mt) -> bool {
+            // FIXME(#6129). Default methods can't deal with autoref.
+            //
+            // I am a horrible monster and I pray for death. Currently
+            // the default method code fails when you try to reborrow
+            // because it is not handling types correctly. In lieu of
+            // fixing that, I am introducing this horrible hack. - ndm
+            self_mt.mutbl == m_imm && ty::type_is_self(self_mt.ty)
+        }
     }
 
     fn search_for_autosliced_method(
diff --git a/src/librustc/middle/typeck/check/mod.rs b/src/librustc/middle/typeck/check/mod.rs
index 84fc40f6954..fb58df3d55c 100644
--- a/src/librustc/middle/typeck/check/mod.rs
+++ b/src/librustc/middle/typeck/check/mod.rs
@@ -2966,7 +2966,8 @@ pub fn check_block(fcx0: @mut FnCtxt, blk: &ast::blk)  {
 pub fn check_block_with_expected(fcx: @mut FnCtxt,
                                  blk: &ast::blk,
                                  expected: Option<ty::t>) {
-    let prev = replace(&mut fcx.ps, fcx.ps.recurse(blk));
+    let purity_state = fcx.ps.recurse(blk);
+    let prev = replace(&mut fcx.ps, purity_state);
 
     do fcx.with_region_lb(blk.node.id) {
         let mut warned = false;
diff --git a/src/librustc/middle/typeck/check/regionck.rs b/src/librustc/middle/typeck/check/regionck.rs
index 1c35c911b14..be513cbb0f3 100644
--- a/src/librustc/middle/typeck/check/regionck.rs
+++ b/src/librustc/middle/typeck/check/regionck.rs
@@ -457,20 +457,18 @@ fn constrain_call(rcx: @mut Rcx,
     let callee_scope = call_expr.id;
     let callee_region = ty::re_scope(callee_scope);
 
-    for fn_sig.inputs.eachi |i, input| {
+    for arg_exprs.each |&arg_expr| {
         // ensure that any regions appearing in the argument type are
         // valid for at least the lifetime of the function:
         constrain_regions_in_type_of_node(
-            rcx, arg_exprs[i].id, callee_region, arg_exprs[i].span);
+            rcx, arg_expr.id, callee_region, arg_expr.span);
 
         // unfortunately, there are two means of taking implicit
         // references, and we need to propagate constraints as a
         // result. modes are going away and the "DerefArgs" code
         // should be ported to use adjustments
-        ty::set_default_mode(tcx, input.mode, ast::by_copy);
-        let is_by_ref = ty::resolved_mode(tcx, input.mode) == ast::by_ref;
-        if implicitly_ref_args || is_by_ref {
-            guarantor::for_by_ref(rcx, arg_exprs[i], callee_scope);
+        if implicitly_ref_args {
+            guarantor::for_by_ref(rcx, arg_expr, callee_scope);
         }
     }