From 9b1c09818ceb27eade66aa2a00689f7908caf5f0 Mon Sep 17 00:00:00 2001
From: WerWolv <werwolv98@gmail.com>
Date: Sun, 17 Oct 2021 21:49:33 +0200
Subject: [PATCH] patterns: Fixed accessing global scope items through the
 parent keyword

---
 .../include/hex/pattern_language/ast_node.hpp  | 18 +++++++++++++++---
 .../include/hex/pattern_language/evaluator.hpp |  7 ++++---
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/plugins/libimhex/include/hex/pattern_language/ast_node.hpp b/plugins/libimhex/include/hex/pattern_language/ast_node.hpp
index 7bb8741f1..d372031f9 100644
--- a/plugins/libimhex/include/hex/pattern_language/ast_node.hpp
+++ b/plugins/libimhex/include/hex/pattern_language/ast_node.hpp
@@ -1526,13 +1526,19 @@ namespace hex::pl {
 
                     if (name == "parent") {
                         scopeIndex--;
+
+                        if (-scopeIndex >= evaluator->getScopeCount())
+                            LogConsole::abortEvaluation("cannot access parent of global scope", this);
+
                         searchScope = *evaluator->getScope(scopeIndex).scope;
                         auto currParent = evaluator->getScope(scopeIndex).parent;
 
-                        if (currParent == nullptr)
-                            LogConsole::abortEvaluation("no parent available", this);
+                        if (currParent == nullptr) {
+                            currPattern = nullptr;
+                        } else {
+                            currPattern = currParent->clone();
+                        }
 
-                        currPattern = currParent->clone();
                         continue;
                     } else if (name == "this") {
                         searchScope = *evaluator->getScope(scopeIndex).scope;
@@ -1592,6 +1598,9 @@ namespace hex::pl {
                     }, index->getValue());
                 }
 
+                if (currPattern == nullptr)
+                    break;
+
                 if (auto pointerPattern = dynamic_cast<PatternDataPointer*>(currPattern)) {
                     auto newPattern = pointerPattern->getPointedAtPattern()->clone();
                     delete currPattern;
@@ -1611,6 +1620,9 @@ namespace hex::pl {
 
             }
 
+            if (currPattern == nullptr)
+                LogConsole::abortEvaluation("cannot reference global scope", this);
+
             return { currPattern };
         }
 
diff --git a/plugins/libimhex/include/hex/pattern_language/evaluator.hpp b/plugins/libimhex/include/hex/pattern_language/evaluator.hpp
index 828035272..8d5e2c8d8 100644
--- a/plugins/libimhex/include/hex/pattern_language/evaluator.hpp
+++ b/plugins/libimhex/include/hex/pattern_language/evaluator.hpp
@@ -45,9 +45,6 @@ namespace hex::pl {
         }
 
         const Scope& getScope(s32 index) {
-            static Scope empty;
-
-            if (index > 0 || -index >= this->m_scopes.size()) return empty;
             return this->m_scopes[this->m_scopes.size() - 1 + index];
         }
 
@@ -55,6 +52,10 @@ namespace hex::pl {
             return this->m_scopes.front();
         }
 
+        size_t getScopeCount() {
+            return this->m_scopes.size();
+        }
+
         bool isGlobalScope() {
             return this->m_scopes.size() == 1;
         }