From 1c4ad95632ccf5692c81343a16a6c6d1099d6cfb Mon Sep 17 00:00:00 2001
From: markopy <48253511+markopy@users.noreply.github.com>
Date: Sat, 8 Feb 2020 22:09:57 +0000
Subject: [PATCH 1/3] Use faster, direct array access in UnionFind.fast_find()

---
 hdbscan/_hdbscan_linkage.pyx | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/hdbscan/_hdbscan_linkage.pyx b/hdbscan/_hdbscan_linkage.pyx
index 80676f38..c818bbdb 100644
--- a/hdbscan/_hdbscan_linkage.pyx
+++ b/hdbscan/_hdbscan_linkage.pyx
@@ -186,11 +186,11 @@ cdef class UnionFind (object):
     cdef np.intp_t fast_find(self, np.intp_t n):
         cdef np.intp_t p
         p = n
-        while self.parent_arr[n] != -1:
-            n = self.parent_arr[n]
+        while self.parent[n] != -1:
+            n = self.parent[n]
         # label up to the root
-        while self.parent_arr[p] != n:
-            p, self.parent_arr[p] = self.parent_arr[p], n
+        while self.parent[p] != n:
+            p, self.parent[p] = self.parent[p], n
         return n
 
 

From 24ee0c3a9f047d23de66bede217df46593a31222 Mon Sep 17 00:00:00 2001
From: markopy <48253511+markopy@users.noreply.github.com>
Date: Mon, 10 Feb 2020 00:15:08 +0000
Subject: [PATCH 2/3] Fix heap corruption in union find

---
 hdbscan/_hdbscan_linkage.pyx | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/hdbscan/_hdbscan_linkage.pyx b/hdbscan/_hdbscan_linkage.pyx
index c818bbdb..cec85f95 100644
--- a/hdbscan/_hdbscan_linkage.pyx
+++ b/hdbscan/_hdbscan_linkage.pyx
@@ -178,9 +178,7 @@ cdef class UnionFind (object):
         self.size[self.next_label] = self.size[m] + self.size[n]
         self.parent[m] = self.next_label
         self.parent[n] = self.next_label
-        self.size[self.next_label] = self.size[m] + self.size[n]
         self.next_label += 1
-
         return
 
     cdef np.intp_t fast_find(self, np.intp_t n):
@@ -188,9 +186,10 @@ cdef class UnionFind (object):
         p = n
         while self.parent[n] != -1:
             n = self.parent[n]
-        # label up to the root
-        while self.parent[p] != n:
-            p, self.parent[p] = self.parent[p], n
+        # label up to the root if this is not the root already
+        if p != n:
+            while self.parent[p] != n:
+                p, self.parent[p] = self.parent[p], n
         return n
 
 

From 682ad87ddf9ab3eb48d42dc9826d2d90c4031da3 Mon Sep 17 00:00:00 2001
From: markopy <48253511+markopy@users.noreply.github.com>
Date: Sat, 3 Oct 2020 16:28:54 +0100
Subject: [PATCH 3/3] Fix issue #321

---
 hdbscan/_hdbscan_linkage.pyx | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/hdbscan/_hdbscan_linkage.pyx b/hdbscan/_hdbscan_linkage.pyx
index cec85f95..8c454d1c 100644
--- a/hdbscan/_hdbscan_linkage.pyx
+++ b/hdbscan/_hdbscan_linkage.pyx
@@ -182,14 +182,16 @@ cdef class UnionFind (object):
         return
 
     cdef np.intp_t fast_find(self, np.intp_t n):
-        cdef np.intp_t p
+        cdef np.intp_t p, tmp
         p = n
         while self.parent[n] != -1:
             n = self.parent[n]
         # label up to the root if this is not the root already
         if p != n:
             while self.parent[p] != n:
-                p, self.parent[p] = self.parent[p], n
+                tmp = self.parent[p]
+                self.parent[p] = n
+                p = tmp
         return n