From bc20e4f71d41f2ebcc56351daecb826544b15df5 Mon Sep 17 00:00:00 2001
From: Ali Mohammad Pur <ali.mpfard@gmail.com>
Date: Fri, 21 Jan 2022 23:44:50 +0330
Subject: [PATCH] LibRegex: Add some more information to Compare::Reference
 debug output

---
 Userland/Libraries/LibRegex/RegexByteCode.cpp | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Userland/Libraries/LibRegex/RegexByteCode.cpp b/Userland/Libraries/LibRegex/RegexByteCode.cpp
index 050f067ae0..e0e6cbe175 100644
--- a/Userland/Libraries/LibRegex/RegexByteCode.cpp
+++ b/Userland/Libraries/LibRegex/RegexByteCode.cpp
@@ -900,6 +900,21 @@ Vector<String> OpCode_Compare::variable_arguments_to_string(Optional<MatchInput>
         } else if (compare_type == CharacterCompareType::Reference) {
             auto ref = m_bytecode->at(offset++);
             result.empend(String::formatted("number={}", ref));
+            if (input.has_value()) {
+                if (state().capture_group_matches.size() > input->match_index) {
+                    auto& match = state().capture_group_matches[input->match_index];
+                    if (match.size() > ref) {
+                        auto& group = match[ref];
+                        result.empend(String::formatted("left={}", group.left_column));
+                        result.empend(String::formatted("right={}", group.left_column + group.view.length_in_code_units()));
+                        result.empend(String::formatted("contents='{}'", group.view));
+                    } else {
+                        result.empend(String::formatted("(invalid ref, max={})", match.size() - 1));
+                    }
+                } else {
+                    result.empend(String::formatted("(invalid index {}, max={})", input->match_index, state().capture_group_matches.size() - 1));
+                }
+            }
         } else if (compare_type == CharacterCompareType::String) {
             auto& length = m_bytecode->at(offset++);
             StringBuilder str_builder;