From 63df8d6f2c1181b329cd3fd4541434fea2b36036 Mon Sep 17 00:00:00 2001
From: Watson <watson1978@gmail.com>
Date: Sun, 18 Aug 2024 22:28:38 +0900
Subject: [PATCH] Do not override Object#to_json with mimic_json

---
 ext/oj/mimic_json.c | 4 +++-
 ext/oj/oj.c         | 7 +++++++
 ext/oj/oj.h         | 2 ++
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/ext/oj/mimic_json.c b/ext/oj/mimic_json.c
index 35ad0896..26b9ebdb 100644
--- a/ext/oj/mimic_json.c
+++ b/ext/oj/mimic_json.c
@@ -905,7 +905,9 @@ oj_define_mimic_json(int argc, VALUE *argv, VALUE self) {
     }
     oj_mimic_json_methods(json);
 
-    rb_define_method(rb_cObject, "to_json", mimic_object_to_json, -1);
+    if (!RTEST(rb_funcall2(rb_cObject, oj_method_defined_p_id, 1, &oj_to_json_sym))) {
+        rb_define_method(rb_cObject, "to_json", mimic_object_to_json, -1);
+    }
 
     rb_gv_set("$VERBOSE", verbose);
 
diff --git a/ext/oj/oj.c b/ext/oj/oj.c
index 8b3354ce..9b8dcc59 100644
--- a/ext/oj/oj.c
+++ b/ext/oj/oj.c
@@ -72,6 +72,7 @@ ID oj_utc_id;
 ID oj_utc_offset_id;
 ID oj_utcq_id;
 ID oj_write_id;
+ID oj_method_defined_p_id;
 
 VALUE oj_bag_class;
 VALUE oj_bigdecimal_class;
@@ -98,6 +99,7 @@ VALUE oj_quirks_mode_sym;
 VALUE oj_safe_sym;
 VALUE oj_symbolize_names_sym;
 VALUE oj_trace_sym;
+VALUE oj_to_json_sym;
 
 static VALUE allow_blank_sym;
 static VALUE allow_gc_sym;
@@ -1887,6 +1889,8 @@ void Init_oj(void) {
     oj_utcq_id         = rb_intern("utc?");
     oj_write_id        = rb_intern("write");
 
+    oj_method_defined_p_id = rb_intern("method_defined?");
+
     rb_require("oj/bag");
     rb_require("oj/error");
     rb_require("oj/mimic");
@@ -2061,6 +2065,9 @@ void Init_oj(void) {
     xss_safe_sym = ID2SYM(rb_intern("xss_safe"));
     rb_gc_register_address(&xss_safe_sym);
 
+    oj_to_json_sym = ID2SYM(oj_to_json_id);
+    rb_gc_register_address(&oj_to_json_sym);
+
     oj_slash_string = rb_str_new2("/");
     rb_gc_register_address(&oj_slash_string);
     OBJ_FREEZE(oj_slash_string);
diff --git a/ext/oj/oj.h b/ext/oj/oj.h
index f6ff51e6..5e61ad4c 100644
--- a/ext/oj/oj.h
+++ b/ext/oj/oj.h
@@ -323,6 +323,7 @@ extern VALUE oj_space_before_sym;
 extern VALUE oj_space_sym;
 extern VALUE oj_symbolize_names_sym;
 extern VALUE oj_trace_sym;
+extern VALUE oj_to_json_sym;
 
 extern VALUE oj_slash_string;
 
@@ -370,6 +371,7 @@ extern ID oj_utc_id;
 extern ID oj_utc_offset_id;
 extern ID oj_utcq_id;
 extern ID oj_write_id;
+extern ID oj_method_defined_p_id;
 
 extern bool oj_use_hash_alt;
 extern bool oj_use_array_alt;