From 6beaf010a447ce9fb35c85f9fb2f41685e2114ba Mon Sep 17 00:00:00 2001
From: Mike Dalessio <mike.dalessio@gmail.com>
Date: Wed, 30 Aug 2023 13:09:02 -0400
Subject: [ruby/yarp] fix: binary CallNode with out-of-order arg and receiver

The snippet added in this commit previously resulted in a CallNode
with inverted start and end locations:

    >   AssocNode(15...13)(
    >     CallNode(15...13)(
            StringNode(15...17)((15...16), (16...16), (16...17), ""),
            nil,
            (12...13),
            nil,
            ArgumentsNode(12...13)([MissingNode(12...13)()]),
            nil,
            nil,
            0,
            "/"
          ),
          MissingNode(13...13)(),
          (13...13)
        ),

which failed an assertion during serialization.

After this change, it looks better:

    >   AssocNode(12...13)(
    >     CallNode(12...17)(
            StringNode(15...17)((15...16), (16...16), (16...17), ""),
            nil,
            (12...13),
            nil,
            ArgumentsNode(12...13)([MissingNode(12...13)()]),
            nil,
            nil,
            0,
            "/"
          ),
          MissingNode(13...13)(),
          (13...13)
        ),

Found by the fuzzer.

https://github.com/ruby/yarp/commit/040aa63ad6
---
 test/yarp/fuzzer_test.rb | 5 +++++
 yarp/yarp.c              | 8 ++++++--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/test/yarp/fuzzer_test.rb b/test/yarp/fuzzer_test.rb
index d75d1422f0..4d7a0af8e7 100644
--- a/test/yarp/fuzzer_test.rb
+++ b/test/yarp/fuzzer_test.rb
@@ -28,5 +28,10 @@ module YARP
       A
       B
     EOF
+    snippet "create a binary call node with arg before receiver", <<~EOF
+      <<-A.g/{/
+      A
+      /, ""\\
+    EOF
   end
 end
diff --git a/yarp/yarp.c b/yarp/yarp.c
index 40d8d3c972..5b8fba9f62 100644
--- a/yarp/yarp.c
+++ b/yarp/yarp.c
@@ -161,6 +161,10 @@ debug_token(yp_token_t * token) {
 
 #endif
 
+/* Macros for min/max.  */
+#define MIN(a,b) (((a)<(b))?(a):(b))
+#define MAX(a,b) (((a)>(b))?(a):(b))
+
 /******************************************************************************/
 /* Lex mode manipulations                                                     */
 /******************************************************************************/
@@ -1240,8 +1244,8 @@ static yp_call_node_t *
 yp_call_node_binary_create(yp_parser_t *parser, yp_node_t *receiver, yp_token_t *operator, yp_node_t *argument) {
     yp_call_node_t *node = yp_call_node_create(parser);
 
-    node->base.location.start = receiver->location.start;
-    node->base.location.end = argument->location.end;
+    node->base.location.start = MIN(receiver->location.start, argument->location.start);
+    node->base.location.end = MAX(receiver->location.end, argument->location.end);
 
     node->receiver = receiver;
     node->message_loc = YP_OPTIONAL_LOCATION_TOKEN_VALUE(operator);
-- 
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