From 007db6c60ecb2fec90c270108fdd11116689d9db Mon Sep 17 00:00:00 2001
From: Piotr Tomiak <piotr.tomiak@jetbrains.com>
Date: Tue, 24 Sep 2024 10:41:57 +0200
Subject: [PATCH] RelaxNg: Avoid NPEs to improve performance when calculating
 element descriptors

GitOrigin-RevId: 9260e29679da728aeba7119accf2214b5dcfd460
---
 .../descriptors/RecursionSaveWalker.java      | 24 ++++++++++++-------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/xml/relaxng/src/org/intellij/plugins/relaxNG/model/descriptors/RecursionSaveWalker.java b/xml/relaxng/src/org/intellij/plugins/relaxNG/model/descriptors/RecursionSaveWalker.java
index d672e6678fa0..0ad4cf6113f0 100644
--- a/xml/relaxng/src/org/intellij/plugins/relaxNG/model/descriptors/RecursionSaveWalker.java
+++ b/xml/relaxng/src/org/intellij/plugins/relaxNG/model/descriptors/RecursionSaveWalker.java
@@ -29,9 +29,11 @@ public class RecursionSaveWalker extends DPatternWalker {
   @Override
   public Void onGrammar(DGrammarPattern p) {
     if (myVisited.add(p)) {
-      try {
-        return super.onGrammar(p);
-      } catch (NullPointerException e) {
+      var start = p.getStart();
+      if (start != null) {
+        return start.accept(this);
+      }
+      else {
         return null; // missing start pattern
       }
     }
@@ -41,9 +43,11 @@ public class RecursionSaveWalker extends DPatternWalker {
   @Override
   public Void onRef(DRefPattern p) {
     if (myVisited.add(p)) {
-      try {
-        return super.onRef(p);
-      } catch (NullPointerException e) {
+      var target = p.getTarget();
+      var pattern = target != null ? target.getPattern() : null;
+      if (pattern != null) {
+        return pattern.accept(this);
+      } else {
         return null; // unresolved ref
       }
     }
@@ -53,9 +57,11 @@ public class RecursionSaveWalker extends DPatternWalker {
   @Override
   protected Void onUnary(DUnaryPattern p) {
     if (myVisited.add(p)) {
-      try {
-        return super.onUnary(p);
-      } catch (NullPointerException e) {
+      var child = p.getChild();
+      if (child != null) {
+        child.accept(this);
+      }
+      else {
         return null; // empty element
       }
     }