From 79d5332a2da0e2743a77480aebfca256a54a962e Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Fri, 27 Sep 2019 21:12:27 +0900
Subject: [PATCH] Drop eliminated catch-entries

Drop catch table entries used in eliminated block, as well as
call_infos.  [Bug #16184]
---
 compile.c                      | 12 ++++++++++++
 test/ruby/test_optimization.rb | 15 +++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/compile.c b/compile.c
index 68c7e5a71d1960..5bd2315b7bdfc6 100644
--- a/compile.c
+++ b/compile.c
@@ -5118,6 +5118,8 @@ compile_if(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, int
     LABEL *then_label, *else_label, *end_label;
     VALUE branches = Qfalse;
     int ci_size, ci_kw_size;
+    VALUE catch_table = ISEQ_COMPILE_DATA(iseq)->catch_table_ary;
+    long catch_table_size = NIL_P(catch_table) ? 0 : RARRAY_LEN(catch_table);
 
     INIT_ANCHOR(cond_seq);
     INIT_ANCHOR(then_seq);
@@ -5132,17 +5134,27 @@ compile_if(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, int
     ci_size = body->ci_size;
     ci_kw_size = body->ci_kw_size;
     CHECK(COMPILE_(then_seq, "then", node_body, popped));
+    catch_table = ISEQ_COMPILE_DATA(iseq)->catch_table_ary;
     if (!then_label->refcnt) {
         body->ci_size = ci_size;
         body->ci_kw_size = ci_kw_size;
+        if (!NIL_P(catch_table)) rb_ary_set_len(catch_table, catch_table_size);
+    }
+    else {
+        if (!NIL_P(catch_table)) catch_table_size = RARRAY_LEN(catch_table);
     }
 
     ci_size = body->ci_size;
     ci_kw_size = body->ci_kw_size;
     CHECK(COMPILE_(else_seq, "else", node_else, popped));
+    catch_table = ISEQ_COMPILE_DATA(iseq)->catch_table_ary;
     if (!else_label->refcnt) {
         body->ci_size = ci_size;
         body->ci_kw_size = ci_kw_size;
+        if (!NIL_P(catch_table)) rb_ary_set_len(catch_table, catch_table_size);
+    }
+    else {
+        if (!NIL_P(catch_table)) catch_table_size = RARRAY_LEN(catch_table);
     }
 
     ADD_SEQ(ret, cond_seq);
diff --git a/test/ruby/test_optimization.rb b/test/ruby/test_optimization.rb
index ed779fe5a85358..6a9e9601f43aa9 100644
--- a/test/ruby/test_optimization.rb
+++ b/test/ruby/test_optimization.rb
@@ -825,4 +825,19 @@ def test_optimized_empty_ensure
       }
     end;
   end
+
+  def test_optimized_rescue
+    assert_in_out_err("", "#{<<~"begin;"}\n#{<<~'end;'}", [], /END \(RuntimeError\)/)
+    begin;
+      if false
+        begin
+          require "some_mad_stuff"
+        rescue LoadError
+          puts "no mad stuff loaded"
+        end
+      end
+
+      raise  "END"
+    end;
+  end
 end