From c101261f452224dbe48abc890b7c78b7713f6c2b Mon Sep 17 00:00:00 2001
From: dearblue <dearblue@users.osdn.me>
Date: Mon, 9 Jan 2023 22:47:37 +0900
Subject: [PATCH] Call `mrb_env_unshare()` in `mrb_top_run()` if necessary

This is to keep the local variables of the previously created blocks consistent in case the `mrbc_context` passed to `mrb_load_exec()` is `NULL` or different.
Switching between `mrbc_context` pointers that are non `NULL` can be done safely by calling `mrbc_cleanup_local_variables()`.

Before this patch, the result of the following code is not as expected.

```console
% cat loadstr.c
#include <mruby.h>
#include <mruby/compile.h>

int
main(int argc, char *argv[])
{
  mrb_state *mrb = mrb_open();

  mrb_load_string(
      mrb,
      "(a, b, c, d, e, f, g) = [1, 2, 3, 4, 5, 6, 7] \n"
      "$lambda = -> { p [a, b, c, d, e, f, g] }");
  mrb_load_string(mrb, "$lambda.call");

  mrb_close(mrb);

  return 0;
}

% $(bin/mruby-config --cc --cflags --ldflags) loadstr.c $(bin/mruby-config --libs) && ./a.out
[main, nil, nil, main, nil, nil, main]
```

Also, since `mrb_env_unshare()` was not used before, the internal stack of simply detached `env` objects could show invalid addresses by `stack_extend()`.
ref. https://github.com/kou/mruby-pp/commit/ef5951aca870183d8767cb61f6414240988ca35e
---
 mrbgems/mruby-compiler/core/parse.y | 1 +
 mrbgems/mruby-compiler/core/y.tab.c | 1 +
 src/vm.c                            | 6 +++++-
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/mrbgems/mruby-compiler/core/parse.y b/mrbgems/mruby-compiler/core/parse.y
index f807be1e4..0a9da0e36 100644
--- a/mrbgems/mruby-compiler/core/parse.y
+++ b/mrbgems/mruby-compiler/core/parse.y
@@ -6764,6 +6764,7 @@ mrbc_cleanup_local_variables(mrb_state *mrb, mrbc_context *c)
     c->syms = NULL;
     c->slen = 0;
   }
+  c->keep_lv = FALSE;
 }
 
 MRB_API void
diff --git a/mrbgems/mruby-compiler/core/y.tab.c b/mrbgems/mruby-compiler/core/y.tab.c
index 0bb243887..9d0b70a3b 100644
--- a/mrbgems/mruby-compiler/core/y.tab.c
+++ b/mrbgems/mruby-compiler/core/y.tab.c
@@ -12964,6 +12964,7 @@ mrbc_cleanup_local_variables(mrb_state *mrb, mrbc_context *c)
     c->syms = NULL;
     c->slen = 0;
   }
+  c->keep_lv = FALSE;
 }
 
 MRB_API void
diff --git a/src/vm.c b/src/vm.c
index b9ff95e5d..ec92fabdf 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -3097,7 +3097,11 @@ mrb_top_run(mrb_state *mrb, const struct RProc *proc, mrb_value self, mrb_int st
     return mrb_vm_run(mrb, proc, self, stack_keep);
   }
   if (mrb->c->ci == mrb->c->cibase) {
-    mrb_vm_ci_env_set(mrb->c->ci, NULL);
+    if (stack_keep == 0) {
+      struct REnv *e = mrb_vm_ci_env(mrb->c->ci);
+      mrb_vm_ci_env_set(mrb->c->ci, NULL);
+      mrb_env_unshare(mrb, e, FALSE);
+    }
     return mrb_vm_run(mrb, proc, self, stack_keep);
   }
   cipush(mrb, 0, CINFO_SKIP, mrb->object_class, NULL, NULL, 0, 0);