From 9c3cbe7571d02890eff2736519a0981235d92a05 Mon Sep 17 00:00:00 2001
From: Mathias Buus <mathiasbuus@gmail.com>
Date: Wed, 8 Nov 2023 23:31:41 +0100
Subject: [PATCH] fix some bugs

---
 lib/bitfield.js        |  2 +-
 lib/remote-bitfield.js | 10 +++++++---
 lib/replicator.js      | 34 ++++++++++++++++++++++------------
 3 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/lib/bitfield.js b/lib/bitfield.js
index 4f408507..f16627b7 100644
--- a/lib/bitfield.js
+++ b/lib/bitfield.js
@@ -43,7 +43,7 @@ class BitfieldPage {
     let i = Math.floor(start / 128)
     const n = i + Math.ceil(length / 128)
 
-    while (i < n) this.tree.update(this.offset * 8 + i++ * 128)
+    while (i <= n) this.tree.update(this.offset * 8 + i++ * 128)
   }
 
   findFirst (val, position) {
diff --git a/lib/remote-bitfield.js b/lib/remote-bitfield.js
index 0386f4e8..b90a8191 100644
--- a/lib/remote-bitfield.js
+++ b/lib/remote-bitfield.js
@@ -38,7 +38,7 @@ class RemoteBitfieldPage {
     let i = Math.floor(start / 128)
     const n = i + Math.ceil(length / 128)
 
-    while (i < n) this.tree.update(this.offset * 8 + i++ * 128)
+    while (i <= n) this.tree.update(this.offset * 8 + i++ * 128)
   }
 
   findFirst (val, position) {
@@ -65,6 +65,7 @@ class RemoteBitfieldSegment {
     this.offset = index * BYTES_PER_SEGMENT
     this.tree = quickbit.Index.from([], BYTES_PER_SEGMENT)
     this.pages = new Array(PAGES_PER_SEGMENT)
+    this.pagesLength = 0
   }
 
   get chunks () {
@@ -76,7 +77,10 @@ class RemoteBitfieldSegment {
   }
 
   add (page) {
-    this.pages[page.index - this.index * PAGES_PER_SEGMENT] = page
+    const pageIndex = page.index - this.index * PAGES_PER_SEGMENT
+    if (pageIndex >= this.pagesLength) this.pagesLength = pageIndex + 1
+
+    this.pages[pageIndex] = page
 
     const chunk = { field: page.bitfield, offset: page.offset }
 
@@ -98,7 +102,7 @@ class RemoteBitfieldSegment {
 
     if (i >= PAGES_PER_SEGMENT) return -1
 
-    while (i < this.pages.length) {
+    while (i < this.pagesLength) {
       const p = this.pages[i]
 
       let index = -1
diff --git a/lib/replicator.js b/lib/replicator.js
index 06201306..4f76c54f 100644
--- a/lib/replicator.js
+++ b/lib/replicator.js
@@ -743,20 +743,23 @@ class Peer {
 
   _clearLocalRange (start, length) {
     if (length === 1) {
-      this.missingBlocks.set(start, false)
+      this.missingBlocks.set(start, this.remoteBitfield.get(start) && !this.core.bitfield.get(start))
       return
     }
 
     const contig = Math.min(this.core.tree.length, this.core.header.hints.contiguousLength)
 
-    if (start < contig) {
+    if (start + length < contig) {
       const delta = contig - start
-      this.missingBlocks.setRange(start, delta)
-      start = contig
-      length -= delta
+      this.missingBlocks.setRange(start, delta, false)
+      return
     }
 
-    if ((start & 31) > 0) start -= (start & 31)
+    const rem = start & 32767
+    if (rem > 0) {
+      start -= rem
+      length += rem
+    }
 
     const end = start + Math.min(length, this.core.tree.length)
     while (start < end) {
@@ -772,11 +775,17 @@ class Peer {
 
   _unclearLocalRange (start, length) {
     if (length === 1) {
-      this.missingBlocks.set(start, this.remoteBitfield.get(start))
+      this.missingBlocks.set(start, this.remoteBitfield.get(start) && !this.core.bitfield.get(start))
       return
     }
 
-    if ((start & 31) > 0) start -= (start & 31)
+    const rem = start & 2097151
+    if (rem > 0) {
+      start -= rem
+      length += rem
+    }
+
+    const fixedStart = start
 
     const end = start + Math.min(length, this.remoteLength)
     while (start < end) {
@@ -788,14 +797,14 @@ class Peer {
       start += 2097152
     }
 
-    this._clearLocalRange(start, length)
+    this._clearLocalRange(fixedStart, length)
   }
 
   onrange ({ drop, start, length }) {
     const has = drop === false
 
     if (length === 1) {
-      this.remoteBitfield.setRange(start, length, has)
+      this.remoteBitfield.set(start, has)
       this.missingBlocks.set(start, has && !this.core.bitfield.get(start))
     } else {
       const rangeStart = this.remoteBitfield.findFirst(!has, start)
@@ -1027,12 +1036,14 @@ class Peer {
     if (r.blocks) {
       let min = -1
       let max = -1
+
       for (let i = r.start; i < r.end; i++) {
         const index = r.blocks[i]
         if (min === -1 || index < min) min = index
         if (max === -1 || index > max) max = index
         if (this.missingBlocks.get(index) === true && this._requestRangeBlock(index, length)) return true
       }
+
       if (min > -1) this._maybeWant(min, max - min)
       return false
     }
@@ -1047,7 +1058,6 @@ class Peer {
 
     while (true) {
       i = this.missingBlocks.findFirst(true, i)
-
       if (i === -1 || i >= end) break
 
       if (this._requestRangeBlock(i, length)) return true
@@ -1061,7 +1071,7 @@ class Peer {
 
       if (i === -1 || i >= off) break
 
-      if (this.core.bitfield.get(i) === false && this._hasTreeParent(i) && this._requestRangeBlock(i, length)) return true
+      if (this._requestRangeBlock(i, length)) return true
       i++
     }