🚀 FrostWire for Android: Massive Relaunch (2025)

We're incredibly excited to announce the biggest overhaul of FrostWire for Android in years, representing two years of dedicated development. This update delivers unprecedented speed, stability, and a renewed commitment to your privacy.

🔒 Core Principle Change: Zero Ads and Tracking

The most significant change is our commitment to a truly private experience:

• 🚫 Complete Ad Removal: We have permanently eliminated all third-party ads and advertising tracking of any kind. We will only offer you our FrostWire compatible VPN recommendations to protect your privacy and ask for your continued support.
• 🧘 Distraction-Free Search: Search is now optimized for speed and focus, with the distraction-free mode enabled by default.

⚡ Performance & Stability: Upgrading the Core Engine

We've integrated the new jlibtorrent 2.0.12.7, bringing hundreds of bug fixes and next-generation features:

New Features

• BitTorrent v2 Protocol Support: Full support for the modern v2 and hybrid v1/v2 protocols.
• New Search Sources: Added Knaben and TorrentCSV search performers for more results.
• Flexible Port Selection: New setting: Settings > Torrent Settings > Incoming Connection Port Range selection.
• Automatic Seeding: Finished HTTP transfers are now seeded automatically if seeding is enabled (matching desktop functionality).

Major Performance Optimizations

• Architectural Overhaul: Achieved a 25-50% reduction in memory allocations and significantly reduced garbage collection pressure.
• Blazing Fast Search: Search sorting has been optimized from $O(n^2 \log n)$ to $O(n \log n)$.
• 8.8x Speed Gains: Title normalization and cleaning is now dramatically faster by eliminating heavy regular expressions.
• Efficient I/O: CPU usage during disk I/O operations is reduced by 30-50% (up to 96% in system write calls) by using buffered I/O.

Critical Crash & Freeze Fixes

• Eliminated ANR Crashes: Fixed numerous ANR (Application Not Responding) crashes in the Transfers list, menu preparation, and playback services by moving blocking tasks to background threads.
• Network API Migration: Fixed critical issues with VPN Guard and Wi-Fi-Only protection by migrating from deprecated network APIs to the modern NetworkCallback API.
  • VPN Guard: Now correctly stops torrents when a VPN is required but not connected.
  • Wi-Fi-Only: Correctly pauses torrent downloads on mobile data.
• Protection Visuals: Added visual status indicators in the transfers screen to show when protections pause downloads.

🔧 Maintenance & Library Upgrades

We've updated the entire internal technology stack for security and modern compatibility:

• Image Loading: Replaced the older Picasso library with the modern Coil image loading library.
• Library Updates: Updated Kotlin, Gradle, OkHttp, and many core AndroidX libraries.
• Removal of Dead Performers: Removed the TorrentDownloads, BTDigg, Torlock, and LimeTorrents search performers due to being permanently offline or unreliable.
• jlibtorrent Updates: Upgraded to jlibtorrent 2.0.x with C++20 compilation, OpenSSL 3.5.2, and Boost 1.88.0.

This update ensures FrostWire is faster, more stable, more private, and ready for years to come!

FrostWire 3.0.12 build 766 DEC/02/2025

• new:Powered by jlibtorrent 2.0.12.7 with bittorrent v2 protocol support with hundreds of bug fixes and performance improvements
• new:No more third party ads or advertising tracking of any kind. Only frostwire support requests, vpn suggestions and promotional free downloads.
• new:Knaben search performer, a new torrent search source
• new:TorrentCSV search performer, a new torrent search source
• new:Settings > Torrent Settings > Incoming Connection Port Range selection
• new:Seed finished HTTP transfers if seeding is enabled (automatically creates torrent of finished download like on desktop)
• new:Dynamic SoundCloud client ID and app version fetching from remote server for uninterrupted service
• new:YT search results now handled via details URL detection (youtube.com)
• new:SearchResultUtils utility class for reusable search result utilities
• new:Telluride dialog now works with generic SearchResult instead of YTSearchResult
• new:Distraction free search now on by default, much better experience
• performance:Search architecture optimizations - 25-50% reduction in memory allocations
• performance:SizeParser utility consolidates duplicate implementations, 200+ lines of code eliminated
• performance:SearchMatcher memory optimization reduces garbage collection pressure by 25%
• performance:YT pattern static initialization and string operation optimization
• performance:PerformersHelper.sanitize() 8.8x speed gains in title normalization by not using a regex and instead simple string replacements
• performance:Optimize stackBlur() with array pooling to reduce allocations
• performance:Added periodic VPN/WiFi protection state monitoring to detect VPN disconnections immediately
• performance:Performance optimized periodic checks run on background thread to keep UI responsive
• performance:Added visual status indicators in transfers screen when protections pause downloads
• performance:Optimize search sorting from O(n² log n) to O(n log n)
• performance:reuse OkHttpClient instances to unlock connection pooling and reduce GC pressure
• performance:Replace global Hashtable throttling with lock-free ConcurrentHashMap in TaskThrottle
• performance:Cache torrent-search date parsers to eliminate per-result SimpleDateFormat allocations
• performance:Use buffered I/O for large transfers in OkHttpClientWrapper.save and ZipUtils.unzip. Up to 96% CPU savings in sys write calls, 30-50% reduction in CPU during I/O operations, search results should come out a lot faster
• performance:Optimize Levenshtein distance allocation footprint in PerformersHelper fuzzy matching
• performance:Optimize hot paths for string sanitizers - eliminate regex compilation overhead in search and scrapes (UrlUtils and StringUtils)
• performance:Optimize hot paths for Logger, ThreadPool, and collection sizing
• performance:Optimize MainApplication startup by deferring heavy initialization
• performance:Optimize RecyclerView onBindViewHolder() hot paths
• crash:ANR crashes in Transfers list when updating transfer state due to blocking JNI calls
• crash:ANR crash in menu preparation - menu visibility now cached on background thread
• crash:ANR crash during transfer list adapter initialization - UI state capture moved to background thread
• crash:ANR crash in transfer detail fragment - download/upload speeds cached on background thread
• crash:ANR crash in onCheckDHT - DHT status updates cached on background thread
• crash:ANR crash in BasePlaylistDialog - removed blocking CountDownLatch.await() on main thread
• crash:ANR crash in transfer list adapter - DiffUtil calculations moved to background thread
• crash:NullPointerException in AbstractConfirmListDialog when "select all" clicked with empty list
• crash:logic bug in PerformersHelper.countMatchedTokens(), matched tokens were not counted correctly
• crash:ForegroundServiceStartNotAllowedException by adding foreground check and error handling
• crash:Android 14+ ForegroundServiceStartNotAllowedException in MusicPlaybackService
• crash:Android JobScheduler alarm limit exceeded crashes by configuring WorkManager
• crash:ClassCastException in SearchResultListAdapter OnLinkClickListener
• crash:HandlerDispatcher NullPointerException crashes in Picasso image loading (removed on build 760)
• crash:NPE in ImageFetcher.loadCurrentArtwork()
• crash:WiFi-Only protection and VPN Guard were broken due to deprecated network API changes
• crash:Migrated network monitoring from deprecated CONNECTIVITY_ACTION broadcasts to modern NetworkCallback API
• crash:WiFi-Only protection now correctly pauses torrent downloads on mobile data when setting is enabled
• crash:VPN Guard protection now correctly stops torrents when VPN is required but not connected
• crash:NullPointerException in BasePlaylistDialog when fragment is detached from activity
• crash:NullPointerException in MusicUtils.getIdForPlaylist() with defensive null check
• crash:NameError in telluride.py query_video() - undefined qjs_path variable
• crash:ConcurrentModificationException in Ssl$FWHostnameVerifier
• crash:Picasso HandlerDispatcher NullPointerException on network state changes when app is backgrounded by keeping Picasso alive instead of shutting down (removed on build 760)
• crash:thread leak and data race in UrlUtils.getFastestMirrorDomain
• freeze:ensure MusicUtils.removeFromPlaylist ContentResolver activity is in the background
• freeze:sorting through too many results could cause an ANR when cleaning up titles
• freeze:ANR in MusicPlaybackService.setDataSource
• freeze:ANR in MusicPlaybackService.playFDs
• freeze:in playFDs
• freeze:in MusicPlaybackService.setDataSource
• maintenance:Guard favorites toast when fragment detached
• maintenance:ProGuard now uses proguard-android-optimize.txt for better code optimization and APK size reduction
• maintenance:Updated gradle plugin to 8.13.1
• maintenance:Updated okhttp3 to 5.3.2
• maintenance:Updated androidx.lifecycle:lifecycle-viewmodel-ktx to 2.10.0
• maintenance:Updated Kotlin to 2.2.21
• maintenance:Updated com.google.gms:google-services to 4.4.4
• maintenance:Updated com.google.android.ump:user-messaging-platform to 4.0.0
• maintenance:SearchTimeoutException provides better diagnostics with performer and domain context
• maintenance:Search package hierarchy flattened, V2 package consolidated
• maintenance:Removed commented imports and debug code
• maintenance:Fixed typo in PREF_KEY_NETWORK_ENABLE_DHT constant (froswire -> frostwire)
• maintenance:Avoid possible context leak on EngineBroadcastReceiver
• maintenance:all license headers are GPL 3.0
• maintenance:archive.org search fixed
• maintenance:ArchiveorgSearchPerformer -> InternetArchiveSearchPerformer
• maintenance:glotorrents search fixed
• maintenance:idope search fixed
• maintenance:magnetdl search fixed
• maintenance:add BitmapFactory.inSampleSize to prevent OOM crashes
• maintenance:Add Bitmap.recycle() to prevent native memory leaks
• maintenance:Replace deprecated setDrawingCacheEnabled() with Canvas API
• refactor:SearchManager tasks to Runnable and remove Thread.yield() from hot path
• removed:TorrentDownloads search performer (site offline permanently)
• removed:BTDigg search performer (protected by Cloudflare, unable to reliably parse search results)
• removed:Torlock search performer (old site is down, new site is malicious)
• removed:LimeTorrents search performer
• replaced:Picasso for Coil image loading library
• yt_dlp-2025.11.12
• org.jetbrains:annotations:26.0.2-1
• androidx.appcompat:appcompat:1.7.1
• androidx.browser:browser:1.9.0
• com.chaquo.python:gradle:16.1.0, now with linked 16KB mode compatible with android compile sdk 36
• org.codehaus.groovy:groovy-all:3.0.25
• com.squareup.picasso3:picasso:3.0.0-alpha06 and refactor of ImageLoader to use it (removed on build 760)
• new: io.coil-kt.coil3:coil:3.0.4 and io.coil-kt.coil3:coil-network-okhttp:3.0.4
• com.google.gms:google-services:4.4.4
• com.google.firebase:firebase-crashlytics-gradle:3.0.6
• androidx.core:core:1.17.0
• androidx.exifinterface:exifinterface:1.4.1
• androidx.lifecycle:lifecycle-viewmodel-ktx:2.10.0
• com.google.android.material:material:1.13.0
• com.google.code.gson:gson:2.13.2
• com.google.re2j:re2j:1.8
• com.squareup.okhttp3:okhttp:5.3.2
• androidx.work:work-runtime-ktx:2.11.0
• com.google.firebase:firebase-bom:34.6.0
• com.google.android.ump:user-messaging-platform:4.0.0
• org.jetbrains.kotlin:kotlin-stdlib-jdk8:2.2.21
• io.coil-kt.coil3:coil:3.3.0
• io.coil-kt.coil3:coil-network-okhttp:3.3.0
• removed: com.applovin:applovin-sdk
• removed: com.applovin.mediation:unityads-adapter
• Maintenance:all license headers are consistent with GPL 3.0
• jlibtorrent:libraries are now compiled with C++20 (ming/windows with C++2a which is the same)
• jlibtorrent:g++-9 upgraded to g++-11 for linux build
• jlibtorrent:new Sha256Hash::swig()
• jlibtorrent:new SessionManager::find(Sha256Hash) and SessionManager::find(TorrentInfo) methods
• jlibtorrent:built with android NDK r28c with 16K page size support
• Android 64-bit binaries are compiled to have 16KB max-page-size
• jlibtorrent:New com.frostwire:jlibtorrent- maven packages for easier integration with gradle/maven
• jlibtorrent:new torrent_handle::get_resume_data() : add_torrent_params
• jlibtorrent:new torrent_handle::get_resume_data(resume_data_flags_t flags) : add_torrent_params
• jlibtorrent:new settings_pack.int_types i2p_inbound_length_variance
• jlibtorrent:new settings_pack.int_types i2p_outbound_length_variance
• jlibtorrent:Jar built with JDK 17 - JAVA_17 compatibility
• jlibtorrentBoost 1.88.0 upgrade
• jlibtorrent:OpenSSL 3.5.2 upgrade (from 1.1.1t)
• jlibtorrent:Upgraded SWIG to 4.3.1
• jlibtorrent:Gradle 9.0.0
• dev: junit upgraded from 4.13.1 -> 4.13.2
• lt:add option to send host header in HTTP proxy CONNECT command
• lt:cache DNS failures for a shorter time
• lt:file_renamed_alert is always posted, regardless of alert mask
• lt:add feature to request resume data synchronously
• lt:don't leak file descriptors to child processes (O_CLOEXEC)
• lt:optimize the utp resend
• lt:optimize tracker announcements
• fix handling of invalid filenames
• add support for I2CP inbound.lengthVariance and outbound.lengthVariance tunnel settings
• lt: validate add_torrent_params::save_path at run-time
• lt: use stricter rules for what filenames are valid on Android
• lt: fix applying IP filter to DHT traffic (HanabishiRecca)
• lt: fix race condition when cancelling requests after becoming a seed
• lt: fix performance bug in the file pool, evicting MRU instead of LRU (HanabishiRecca)
• lt: fix bug where file_progress could sometimes be reported as >100%
• jlibtorrent:BDecodeNode: hasList, hasDict, hasString, hasInt, getList, getDict, getString, getInt
• lt:limit piece size in torrent creator
• lt:don't hint FADV_RANDOM on posix systems. May improve seeding performance
• lt:allow boost connect while checking resume data if no_verify_files flag is set
• lt:fix BEP-40 peer priority for IPv6
• lt:fix file pre-allocation when changing file priority (HanabishiRecca)
• jlibtorrent:SWIG interface files have been modularized for better maintainability and readability
• jlibtorrent:Added missing alert types
• jlibtorrent:Introduced typed_bitfield template
• jlibtorrent:Operator renaming for Java compatibility
• jlibtorrent:Included boost_system_error_code.i
• jlibtorrent:Added prepare-macos.sh script
• jlibtorrent:Updated run-swig.sh script
• jlibtorrent:Set TORRENT_ABI_VERSION=4
• jlibtorrent:Libtorrent updated to RC_2_0 (rev:2ab8fedabb7716947edc77958da6d0b5e1040df9)
• jlibtorrent:Android NDK r26d (LTS) upgrade (from r25c)
• jlibtorrent:Added --swig-only and --build-only options to swig/build scripts
• jlibtorrent:Added prepare-macos.sh script for macOS build setup
• jlibtorrent:Updated run-swig.sh script for improved SWIG processing
• jlibtorrent:Enhanced exception handling in SWIG interfaces
• jlibtorrent:Fixed issues in file_storage.hpp and ip_filter.hpp
• jlibtorrent:Adjusted build flags and macros for Boost and libtorrent compatibility
• jlibtorrent:Enabled SWIG directors for specific classes
• lt:fix uTP issue where closing the connection could corrupt the payload
• lt:apply DSCP/TOS to sockets before initiating the TCP connection
• lt:assume copy_file_range() exists on linux (unless old glibc)
• lt:fix issue where set_piece_deadline() did not correctly post read_piece_alert
• lt:fix integer overflow in piece picker
• lt:torrent_status::num_pieces counts pieces passed hash check, as documented
• lt:check settings_pack::max_out_request_queue before performance alert
• lt:allow on_unknown_torrent method in the absence of active torrents (new plugin feature added)
• lt:add feature to async_move_storage() to not move files
• lt:fix reject resume data if it contains mismatching info hashes
• lt:fix clear the candidate_cache when clear peer_list
• lt:fix missing python converter for dht::announce_flags_t
• lt:fix issue with web seed connections when they close and re-open
• lt:fallocate() not supported is not a fatal error
• lt:fix proxying of IPv6 connections via IPv4 proxy
• lt:treat CGNAT address range as local IPs
• lt:add stricter checking of piece layers when loading torrents
• lt:add stricter checking of v1 and v2 hashes being consistent
• lt:cache failed DNS lookups as well as successful ones
• lt:add an i2p torrent state to control interactions with clear swarms
• lt:fix i2p SAM protocol parsing of quoted messages
• lt:expose i2p peer destination in peer_info
• lt:fix i2p tracker announces
• lt:fix issue with read_piece() stopping torrent on pieces not yet downloaded
• lt:improve handling of allow_i2p_mixed setting to work for magnet links
• lt:fix web seed request for renamed single-file torrents
• lt:fix issue where web seeds could disappear from resume data
• lt:extend save_resume with additional conditional flags
• lt:fix issue with retrying trackers in tiers > 0
• lt:fix last_upload and last_download resume data fields to use posix time
• lt:improve error messages for no_connect_privileged_ports, by untangle it from the port filter
• lt:fix I2P issue introduced in 2.0.0
• lt:add async tracker status query, post_trackers()
• lt:add async torrent status query, post_status()
• lt:support loading version 2 of resume data format
• lt:fix issue with odd piece sizes
• lt:add async piece availability query, post_piece_availability()
• lt:add async download queue query, post_download_queue()
• lt:add async file_progress query, post_file_progress()
• lt:add async peer_info query, post_peer_info()
• lt:fix uTP streams timing out instead of closing cleanly
• lt:add write_torrent_file_buf() overload for generating .torrent files
• lt:add create_torrent::generate_buf() function to generate into a buffer
• lt:fix copy_file when the file ends with a sparse region
• lt:uTP performance, fix packet loss when sending is stalled
• lt:fix trackers being stuck after session pause/resume
• lt:fix bug in hash_picker with empty files
• lt:uTP performance, prevent premature timeouts/resends
• lt:add option to not memory map files below a certain size
• lt:settings_pack now returns default values when queried for missing settings
• lt:fix copy_file fall-back when SEEK_HOL/SEEK_DATA is not supported
• lt:improve error reporting from file copy and move
• lt:tweak pad file placement to match reference implementation (tail-padding)
• lt:uTP performance, more lenient nagle's algorithm to always allow one outstanding undersized packet
• lt:uTP performance, piggy-back held back undersized packet with ACKs
• lt:uTP performance, don't send redundant deferred ACKs
• lt:support incoming SOCKS5 packets with hostnames as source address, for UDP trackers
• lt:ignore duplicate network interface change notifications on linux
• lt:fix total_want/want accounting when forcing a recheck
• lt:fix merging metadata with magnet links added on top of existing torrents
• lt:add torrent_flag to default all file priorities to dont_download
• lt:fix &so= feature in magnet links
• lt:improve compatibility of SOCKS5 UDP ASSOCIATE
• lt:fix madvise range for flushing cache in mmap_storage
• lt:open files with no_cache set in O_SYNC mode~
• lt:fix issue in use of copy_file_range() on linux
• lt:avoid open-file race in the file_view_pool
• lt:fix issue where stop-when-ready would not close files
• lt:fix issue with duplicate hybrid torrent via separate v1 and v2 magnet links
• lt:added new function to load torrent files, load_torrent_*()
• lt:support sync_file_range() on linux
• lt:fix issue in write_torrent_file() when file size is exactly piece size
• lt:fix file_num_blocks() and file_num_pieces() for empty files
• lt:add new overload to make_magnet_uri()
• lt:add missing protocol version to tracker_reply_alert and tracker_error_alert
• lt:fix privilege issue with SetFileValidData()
• lt:add asynchronous overload of torrent_handle::add_piece()
• lt:default to a single hashing thread, for full checks
• lt:Fix bug when checking files and the first piece is invalid
• lt:fix issue creating a v2 torrent from torrent_info containing an empty file
• lt:make recheck files also update which files use partfile
• lt:add write_through disk_io_write_mode, which flushes pieces to disk immediately
• lt:improve copy file function to preserve sparse regions (when supported)
• lt:add function to truncate over-sized files part of a torrent
• lt:fix directory creation on windows shared folders
• lt:add flag to make add_files() not record file attributes
• lt:deprecate (unused) allow_partial_disk_writes settings
• lt:fix disk-full error reporting in mmap_disk_io
• lt:fixed similar-torrents feature for v2 torrents
• lt:fix potential unbounded recursion in add_completed_job, in disk I/O
• lt:deprecated (unused) volatile_read_cache setting
• lt:fix part files being marked as hidden on window
• lt:on windows, explicitly flush memory mapped files periodically
• lt:fix build with WolfSSL
• lt:fix issue where incoming uTP connections were not accepted over SOCKS5
• lt:fix several issues in handling of checking files of v2 torrents, esp. from magnet links
• lt:make the token limit when parsing metadata from magnet files configurable
• lt:fix issue with stalled pieces on disk full errors
• lt:fix missing python binding for file_progress_flags
• lt:fix torrent_file_with_hashes() to fail when we don't have the piece layers
• lt:restore path character encoding conversion for non UTF-8 locales on linux
• lt:fix use-after-free bug in make_magnet_uri
• lt:add write_torrent_file() to produce a .torrent file from add_torrent_params
• lt:allow loading v2 .torrent files without piece layer
• lt:fix issue with adding v2 torrents with invalid file root hash
• lt:fix piece picker bug causing double-picks with prefer-contiguous enabled
• lt:expose session_params in python bindings
• lt:fix (deprecated) use of add_torrent_params::info_hash
• lt:fix issue creating and loading v2 torrents with empty files. Improves conformance to BEP52 reference implementation
• lt:add new torrent_file_with_hashes() which includes piece layers for creating .torrent files
• lt:add file_prio_alert, posted when file priorities are updated
• lt:fix issue where set_piece_hashes() would not propagate file errors
• lt:add missing python binding for event_t
• lt:add work-around for systems without fseeko() (such as Android)
• lt:add convenience header libtorrent/libtorrent.hpp
• lt:increase default max_allowed_in_request_queue
• lt:fix loading non-ascii filenames on windows with torrent_info constructor (2.0 regression)
• lt:add std::hash<> specialization for info_hash_t
• lt:fix integer overflow in hash_picker and properly restrict max file sizes in torrents
• lt:strengthen SSRF mitigation for web seeds
• lt:add v1() and v2() functions to torrent_info
• lt:fix piece_layers() to work for single-piece files
• lt:fix python binding regression in session constructor flags
• lt:fix unaligned piece requests in mmap_storage
• lt:improve client_data_t ergonomics
• lt:fix issue with concurrent access to part files
• lt:fix attribute in single-file v2 torrent creation
• lt:fix padding for empty files in v2 torrent creation
• lt:add function to ask a file_storage whether it's v2 or not
• lt:fix mtime field when creating single-file v2 torrents
• lt:fix performance regression in checking files
• lt:disable use of SetFileValidData() by default (windows). A new setting allows enabling it
• lt:dropped dependency on iconv
• lt:deprecate set_file_hash() in torrent creator, as it's superceded by v2 torrents
• lt:deprecate mutable access to info_section in torrent_info
• lt:removed deprecated lazy_entry/lazy_bdecode
• lt:stats_alert deprecated
• lt:remove bittyrant choking algorithm
• lt:update userdata in add_torrent_params to be type-safe and add to torrent_handle
• lt:add ip_filter to session_params
• lt:added support for wolfSSL for SHA-1 hash and HTTPS (no Torrents over SSL)
• lt:requires OpenSSL minimum version 1.0.0 with SNI support
• lt:deprecated save_state() and load_state() on session in favour of new
• lt:write_session_params() and read_session_params()
• lt:added support for BitTorrent v2 (see docs/upgrade_to_2.0.html)
• lt:create_torrent() pad_file_limit parameter removed
• lt:create_torrent() merkle- and optimize-alignment flags removed
• lt:merkle_tree removed from add_torrent_params
• lt:announce_entry expose information per v1 and v2 info-hash announces
• lt:deprecated sha1_hash info_hash members on torrent_removed_alert,
• lt:torrent_deleted_alert, torrent_delete_failed_alert and add_torrent_params
• lt:undeprecate error_file_metadata for torrent errors related to its metadata
• lt:remove support for adding a torrent under a UUID (used for previous RSS support)
• lt:remove deprecated feature to add torrents by file:// URL
• lt:remove deprecated feature to download .torrent file from URL
• lt:requires boost >= 1.66 to build
• lt:update networking API to networking TS compatible boost.asio
• lt:overhauled disk I/O subsystem to use memory mapped files (where available)
• lt:libtorrent now requires C++14 to build
• lt:added support for GnuTLS for HTTPS and torrents over SSL
• lt:fix issue where stop-when-ready would not close files
• lt:uTP performance, fix packet loss when sending is stalled
• lt:uTP performance, prevent premature timeouts/resends
• lt:uTP performance, more lenient nagle's algorithm to always allow one outstanding undersized packet
• lt:uTP performance, piggy-back held back undersized packet with ACKs
• lt:uTP performance, don't send redundant deferred ACKs
• lt:fix wanted_done/done accounting when force-rechecking
• lt:expose userdata via torrent_handle (back-port from 2.0)
• lt:fix renaming of filenames that are too long for the filesystem
• lt:made UPnP and LSD code avoid using select_reactor (to work around an issue on windows in boost.asio < 1.80)