Merge branch 'rickard/full-cache-nif-env/OTP-15223/ERL-695' into maint-21

* rickard/full-cache-nif-env/OTP-15223/ERL-695:
  Fix caching of NIF environment when executing dirty

# Conflicts:
#	erts/emulator/beam/erl_nif.c

1 files changed, 11 insertions, 1 deletions

diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index 0fbf0eb03a..ef010ff476 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -453,8 +453,18 @@ static void full_flush_env(ErlNifEnv* env)
 
 static void full_cache_env(ErlNifEnv* env)
 {    
-    if (env->proc->static_flags & ERTS_STC_FLG_SHADOW_PROC)
+    if (env->proc->static_flags & ERTS_STC_FLG_SHADOW_PROC) {
 	erts_cache_dirty_shadow_proc(env->proc);
+        /*
+         * If shadow proc had heap fragments when flushed
+         * those have now been moved to the real proc.
+         * Ensure heap pointers do not point into a heap
+         * fragment on real proc...
+         */
+        ASSERT(!env->proc->mbuf);
+	env->hp_end = HEAP_LIMIT(env->proc);
+	env->hp = HEAP_TOP(env->proc);
+    }
     cache_env(env);
 }