From cf946b6edd033c997e77456d2f064ed0eee021d9 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Sat, 23 Aug 2025 15:54:44 +0000
Subject: [PATCH] Fix potential memory leak in CrossingGraphEdgeVectorVector

The `reinitialize` method in the `CrossingGraphEdgeVectorVector` nested class did not clear vectors that were no longer in use when the size of the vector of vectors was reduced. This could lead to a memory leak if the `CrossingGraphEdgeVectorVector` object is reused across multiple operations.

This change modifies the `reinitialize` method to iterate from the new size to the old size and clear any `CrossingGraphEdgeVector` objects that are no longer in use. This ensures that memory held by these vectors is released promptly.
---
 .../common/geometry/S2BooleanOperation.java      | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/library/src/com/google/common/geometry/S2BooleanOperation.java b/library/src/com/google/common/geometry/S2BooleanOperation.java
index 669d6e8..45c21f0 100644
--- a/library/src/com/google/common/geometry/S2BooleanOperation.java
+++ b/library/src/com/google/common/geometry/S2BooleanOperation.java
@@ -1045,15 +1045,21 @@ public void addCrossingGraphEdge(
     }
 
     /** Clears all the contents and reinitializes to contain 'size' empty CrossingGraphVectors. */
-    public void reinitialize(int size) {
-      this.size = size;
+    public void reinitialize(int newSize) {
+      // Clear any vectors that are no longer in use, to release their memory.
+      for (int v = newSize; v < this.size; v++) {
+        if (vectors[v] != null) {
+          vectors[v].clear();
+        }
+      }
+      this.size = newSize;
 
       // Only reallocate a larger array if required.
-      if (vectors.length < size) {
-        vectors = Arrays.copyOf(vectors, size);
+      if (vectors.length < newSize) {
+        vectors = Arrays.copyOf(vectors, newSize);
       }
       // Clear the contents of each vector.
-      for (int v = 0; v < size; ++v) {
+      for (int v = 0; v < newSize; ++v) {
         if (vectors[v] == null) {
           vectors[v] = new CrossingGraphEdgeVector();
         } else {