From 4379baa95af32e7351473831e0d369ba689e4593 Mon Sep 17 00:00:00 2001
From: Yusuke Endoh <mame@ruby-lang.org>
Date: Fri, 3 Apr 2026 19:57:13 +0900
Subject: [PATCH] Fix BotFilter to restore types when base exits bot-only state

When a BotFilter's base_vtx transitions from bot-only to having
non-bot types, previously suppressed variable types were not restored.
This caused variables assigned inside begin/rescue blocks to lose
their types when the rescue clause contained raise (bot).

The fix adds type restoration in on_type_added when the base_vtx
is no longer bot-only.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 lib/typeprof/core/graph/filter.rb |  3 +++
 scenario/flow/begin_rescue_var.rb | 19 +++++++++++++++++++
 2 files changed, 22 insertions(+)
 create mode 100644 scenario/flow/begin_rescue_var.rb

diff --git a/lib/typeprof/core/graph/filter.rb b/lib/typeprof/core/graph/filter.rb
index a41bd53aa..06ada7aaf 100644
--- a/lib/typeprof/core/graph/filter.rb
+++ b/lib/typeprof/core/graph/filter.rb
@@ -114,6 +114,9 @@ def on_type_added(genv, src_var, added_types)
       if src_var == @base_vtx
         if @base_vtx.types.size == 1 && @base_vtx.types.include?(genv.bot_type)
           @next_vtx.on_type_removed(genv, self, @types.keys & @next_vtx.types.keys) # XXX: smoke/control/bot2.rb
+        else
+          # base_vtx is no longer bot-only; restore any previously suppressed types
+          @next_vtx.on_type_added(genv, self, @types.keys - @next_vtx.types.keys)
         end
       else
         added_types.each do |ty|
diff --git a/scenario/flow/begin_rescue_var.rb b/scenario/flow/begin_rescue_var.rb
new file mode 100644
index 000000000..70db7ccc8
--- /dev/null
+++ b/scenario/flow/begin_rescue_var.rb
@@ -0,0 +1,19 @@
+## update
+def test(cond, val)
+  if cond
+    begin
+      val = val.to_i
+    rescue
+      raise "bad"
+    end
+  end
+  val
+end
+
+test(true, "42")
+test(false, "hello")
+
+## assert
+class Object
+  def test: (bool, String) -> (Integer | String)
+end