[committed 47/88] gccrs: Clear the substitution callbacks when copying ArgumentMappings

[arthur.cohen@embecosm.com]

From: Philip Herron <herron.philip@googlemail.com>

When we set the callback on substitutions this is not safe to be copied
around since we store the used argument mappings and can reuse them in
different contexts. This clears the callback on copy's to make it safer.

Signed-off-by: Philip Herron <herron.philip@googlemail.com>

gcc/rust/ChangeLog:

	* typecheck/rust-tyty-subst.cc: update copy constructors
---
 gcc/rust/typecheck/rust-tyty-subst.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/gcc/rust/typecheck/rust-tyty-subst.cc b/gcc/rust/typecheck/rust-tyty-subst.cc
index a5d738744fc..0e181efb359 100644
--- a/gcc/rust/typecheck/rust-tyty-subst.cc
+++ b/gcc/rust/typecheck/rust-tyty-subst.cc
@@ -241,7 +241,7 @@ SubstitutionArgumentMappings::SubstitutionArgumentMappings (
 SubstitutionArgumentMappings::SubstitutionArgumentMappings (
   const SubstitutionArgumentMappings &other)
   : mappings (other.mappings), binding_args (other.binding_args),
-    locus (other.locus), param_subst_cb (other.param_subst_cb),
+    locus (other.locus), param_subst_cb (nullptr),
     trait_item_flag (other.trait_item_flag)
 {}
 
@@ -252,7 +252,7 @@ SubstitutionArgumentMappings::operator= (
   mappings = other.mappings;
   binding_args = other.binding_args;
   locus = other.locus;
-  param_subst_cb = other.param_subst_cb;
+  param_subst_cb = nullptr;
   trait_item_flag = other.trait_item_flag;
 
   return *this;
-- 
2.40.0