Fix current section update issues

src/main/java/ch/njol/skript/lang/Section.java

@@ -27,6 +27,7 @@
 import org.bukkit.event.Event;
 import org.eclipse.jdt.annotation.Nullable;
 
+import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 import java.util.function.Supplier;
@@ -81,12 +82,17 @@ public abstract boolean init(Expression<?>[] expressions,
 	 * (although the loaded code may change it), the calling code must deal with this.
 	 */
 	protected void loadCode(SectionNode sectionNode) {
-		List<TriggerSection> currentSections = getParser().getCurrentSections();
-		currentSections.add(this);
+		ParserInstance parser = getParser();
+		List<TriggerSection> previousSections = parser.getCurrentSections();
+
+		List<TriggerSection> sections = new ArrayList<>(previousSections);
+		sections.add(this);
+		parser.setCurrentSections(sections);
+
 		try {
 			setTriggerItems(ScriptLoader.loadItems(sectionNode));
 		} finally {
-			currentSections.remove(currentSections.size() - 1);
+			parser.setCurrentSections(previousSections);
 		}
 	}
 

src/main/java/ch/njol/skript/lang/TriggerSection.java

@@ -24,6 +24,7 @@
 import org.bukkit.event.Event;
 import org.eclipse.jdt.annotation.Nullable;
 
+import java.util.ArrayList;
 import java.util.List;
 
 /**
@@ -42,12 +43,17 @@ protected TriggerSection(List<TriggerItem> items) {
 	}
 
 	protected TriggerSection(SectionNode node) {
-		List<TriggerSection> currentSections = ParserInstance.get().getCurrentSections();
-		currentSections.add(this);
+		ParserInstance parser = ParserInstance.get();
+		List<TriggerSection> previousSections = parser.getCurrentSections();
+
+		List<TriggerSection> sections = new ArrayList<>(previousSections);
+		sections.add(this);
+		parser.setCurrentSections(sections);
+
 		try {
 			setTriggerItems(ScriptLoader.loadItems(node));
 		} finally {
-			currentSections.remove(currentSections.size() - 1);
+			parser.setCurrentSections(previousSections);
 		}
 	}
 

src/test/skript/tests/regressions/6843-current section reference issue.sk

@@ -0,0 +1,9 @@
+test "outdated current section references":
+	parse:
+		loop {_list::*}:
+			spawn a sheep at {_loc}:
+				set {_e} to event-entity
+		loop {_list::*}:
+			set {_var} to loop-value
+			set {_var} to loop-value-1
+	assert last parse logs is not set with "loop-value and loop-value-1 should've worked"