From 1838dbf6e7f9335e5ad23d9856bd014d18446f07 Mon Sep 17 00:00:00 2001
From: Peter Zhu <peter@peterzhu.ca>
Date: Mon, 22 Jan 2024 15:13:33 -0500
Subject: [PATCH] [PRISM] Fix splat and block in aset

---
 prism_compile.c                 | 4 ++++
 test/ruby/test_compile_prism.rb | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/prism_compile.c b/prism_compile.c
index 8c4f0fed0a..e5ba24115d 100644
--- a/prism_compile.c
+++ b/prism_compile.c
@@ -2713,6 +2713,10 @@ pm_compile_call(rb_iseq_t *iseq, const pm_call_node_t *call_node, LINK_ANCHOR *c
     if (pm_node->flags & PM_CALL_NODE_FLAGS_ATTRIBUTE_WRITE) {
         if (flags & VM_CALL_ARGS_BLOCKARG) {
             ADD_INSN1(ret, &dummy_line_node, topn, INT2FIX(1));
+            if (flags & VM_CALL_ARGS_SPLAT) {
+                ADD_INSN1(ret, &dummy_line_node, putobject, INT2FIX(-1));
+                ADD_SEND_WITH_FLAG(ret, &dummy_line_node, idAREF, INT2FIX(1), INT2FIX(0));
+            }
             ADD_INSN1(ret, &dummy_line_node, setn, INT2FIX(orig_argc + 3));
             PM_POP;
         }
diff --git a/test/ruby/test_compile_prism.rb b/test/ruby/test_compile_prism.rb
index 7705959f4c..fd5787e467 100644
--- a/test/ruby/test_compile_prism.rb
+++ b/test/ruby/test_compile_prism.rb
@@ -1771,6 +1771,15 @@ end
         obj[&p] = 4
       RUBY
 
+      # Test splat and block inside of []=
+      assert_prism_eval(<<~RUBY)
+        obj = Object.new
+        def obj.[]=(a, b); end
+
+        p = proc {}
+        obj[*[1], &p] = 4
+      RUBY
+
       assert_prism_eval(<<-CODE)
         def self.prism_opt_var_trail_hash(a = nil, *b, c, **d); end
         prism_opt_var_trail_hash("a")