Handle overwriting Object::ENV in spawn

Instead of looking for Object::ENV (which can be overwritten),
directly look for the envtbl variable.  As that is static in hash.c,
and the lookup code is in process.c, add a couple non-static
functions that will return envtbl (or envtbl#to_hash).

Fixes [Bug #18164]

1 files changed, 12 insertions, 0 deletions

diff --git a/hash.c b/hash.c
index f75e39430c..fd21a99be0 100644
--- a/hash.c
+++ b/hash.c
@@ -6182,6 +6182,18 @@ env_to_hash(void)
     return hash;
 }
 
+VALUE
+rb_envtbl(void)
+{
+    return envtbl;
+}
+
+VALUE
+rb_env_to_hash(void)
+{
+    return env_to_hash();
+}
+
 /*
  * call-seq:
  *   ENV.to_hash -> hash of name/value pairs