feat(config): add per-host/bucket extra args for SSH, S3, and FTP

Problem: `extra_scp_args`, `extra_s3_args`, and `extra_curl_args` are
global — there's no way to pass adapter-specific args only to a single
host or bucket (e.g. `-O` for a Synology NAS that requires legacy SCP
protocol, or `--endpoint-url` for an R2 bucket).

Solution: add `ssh_hosts`, `s3_buckets`, and `ftp_hosts` config tables
that map exact hostnames/bucket names to per-target arg lists. Per-target
args are appended after the global args at call time. The `scp()` helper
in `ssh.lua` accepts a `hosts` list so cross-host copies deduplicate
host lookups. `create_s3_command` in `s3fs.lua` extracts the bucket from
the command args with no call-site changes needed. `resolved_curl_args`
in `ftp.lua` is called by both `curl()` and `ftpcmd()`.

Based on: stevearc/oil.nvim#607

doc/oil.txt

@@ -175,6 +175,21 @@ The full list of options with their defaults:
       extra_s3_args = {},
       -- Extra arguments to pass to curl for FTP operations
       extra_curl_args = {},
+      -- Per-host SCP arg overrides. Args are appended after global extra_scp_args.
+      -- Keys are exact hostnames as they appear in the SSH URL.
+      ssh_hosts = {
+        -- ["myserver.com"] = { extra_scp_args = { "-O" } },
+      },
+      -- Per-bucket S3 arg overrides. Args are appended after global extra_s3_args.
+      -- Keys are exact S3 bucket names.
+      s3_buckets = {
+        -- ["my-r2-bucket"] = { extra_s3_args = { "--endpoint-url", "https://..." } },
+      },
+      -- Per-host curl arg overrides for FTP. Args are appended after global extra_curl_args.
+      -- Keys are exact hostnames as they appear in the FTP URL.
+      ftp_hosts = {
+        -- ["ftp.internal.com"] = { extra_curl_args = { "--insecure" } },
+      },
       -- EXPERIMENTAL support for performing file operations with git
       git = {
         -- Return true to automatically git add/mv/rm files
@@ -337,6 +352,35 @@ preview_win.max_file_size                          *oil.preview_win*
     than this limit will show a placeholder message instead of being loaded.
     Set to `nil` to disable the limit.
 
+ssh_hosts                                                        *oil.ssh_hosts*
+    type: `table<string, {extra_scp_args?: string[]}>` default: `{}`
+    Per-host SCP argument overrides. Keys are exact hostnames as they appear
+    in the SSH URL. Per-host args are appended after the global
+    `extra_scp_args`. Example: >lua
+        ssh_hosts = {
+          ["nas.local"] = { extra_scp_args = { "-O" } },
+        }
+<
+
+s3_buckets                                                      *oil.s3_buckets*
+    type: `table<string, {extra_s3_args?: string[]}>` default: `{}`
+    Per-bucket S3 argument overrides. Keys are exact S3 bucket names.
+    Per-bucket args are appended after the global `extra_s3_args`. Example: >lua
+        s3_buckets = {
+          ["my-r2-bucket"] = { extra_s3_args = { "--endpoint-url", "https://..." } },
+        }
+<
+
+ftp_hosts                                                        *oil.ftp_hosts*
+    type: `table<string, {extra_curl_args?: string[]}>` default: `{}`
+    Per-host curl argument overrides for FTP operations. Keys are exact
+    hostnames as they appear in the FTP URL. Per-host args are appended after
+    the global `extra_curl_args`. Example: >lua
+        ftp_hosts = {
+          ["ftp.internal.com"] = { extra_curl_args = { "--insecure" } },
+        }
+<
+
 --------------------------------------------------------------------------------
 API                                                                      *oil-api*
 

doc/upstream.md

@@ -99,7 +99,7 @@ issues against this fork.
 | [#578](https://github.com/stevearc/oil.nvim/issues/578) | Hidden file dimming recipe                                 | fixed                                                                                                                                                                                     |
 | [#587](https://github.com/stevearc/oil.nvim/issues/587) | Alt+h keymap                                               | not actionable — user config issue                                                                                                                                                        |
 | [#599](https://github.com/stevearc/oil.nvim/issues/599) | user:group display and manipulation                        | consolidated into [#126](https://github.com/barrettruth/canola.nvim/issues/126)                                                                                                           |
-| [#607](https://github.com/stevearc/oil.nvim/issues/607) | Per-host SCP args                                          | open                                                                                                                                                                                      |
+| [#607](https://github.com/stevearc/oil.nvim/issues/607) | Per-host SCP args                                          | fixed                                                                                                                                                                                     |
 | [#609](https://github.com/stevearc/oil.nvim/issues/609) | Cursor placement via Snacks picker                         | not actionable — Windows-only                                                                                                                                                             |
 | [#612](https://github.com/stevearc/oil.nvim/issues/612) | Delete buffers on file delete                              | fixed                                                                                                                                                                                     |
 | [#615](https://github.com/stevearc/oil.nvim/issues/615) | Cursor at name column on o/O                               | fixed ([#72](https://github.com/barrettruth/canola.nvim/pull/72))                                                                                                                         |

lua/oil/adapters/ftp.lua

@@ -106,6 +106,17 @@ local function curl_ftp_url(url)
   return table.concat(pieces, '')
 end
 
+---@param host string
+---@return string[]
+local function resolved_curl_args(host)
+  local extra = vim.deepcopy(config.extra_curl_args)
+  local host_cfg = config.ftp_hosts[host]
+  if host_cfg and host_cfg.extra_curl_args then
+    vim.list_extend(extra, host_cfg.extra_curl_args)
+  end
+  return extra
+end
+
 ---@param url oil.ftpUrl
 ---@param py_lines string[]
 ---@param cb fun(err: nil|string)
@@ -113,8 +124,8 @@ local function ftpcmd(url, py_lines, cb)
   local lines = {}
   local use_tls = url.scheme == 'oil-ftps://'
   if use_tls then
-    local insecure = vim.tbl_contains(config.extra_curl_args, '--insecure')
+    local curl_args = resolved_curl_args(url.host)
-      or vim.tbl_contains(config.extra_curl_args, '-k')
+    local insecure = vim.tbl_contains(curl_args, '--insecure') or vim.tbl_contains(curl_args, '-k')
     table.insert(lines, 'import ftplib, ssl')
     table.insert(lines, 'ctx = ssl.create_default_context()')
     if insecure then
@@ -170,7 +181,7 @@ local function curl(url, extra_args, opts, cb)
   end
   local cmd = { 'curl', '-sS', '--netrc-optional' }
   vim.list_extend(cmd, ssl_args(url))
-  vim.list_extend(cmd, config.extra_curl_args)
+  vim.list_extend(cmd, resolved_curl_args(url.host))
   vim.list_extend(cmd, extra_args)
   shell.run(cmd, opts, cb)
 end

lua/oil/adapters/s3/s3fs.lua

@@ -46,8 +46,22 @@ end
 ---@param cmd string[] cmd and flags
 ---@return string[] Shell command to run
 local function create_s3_command(cmd)
+  local bucket
+  for _, arg in ipairs(cmd) do
+    bucket = arg:match('^s3://([^/]+)')
+    if bucket then
+      break
+    end
+  end
+  local extra = vim.deepcopy(config.extra_s3_args)
+  if bucket then
+    local bucket_cfg = config.s3_buckets[bucket]
+    if bucket_cfg and bucket_cfg.extra_s3_args then
+      vim.list_extend(extra, bucket_cfg.extra_s3_args)
+    end
+  end
   local full_cmd = vim.list_extend({ 'aws', 's3' }, cmd)
-  return vim.list_extend(full_cmd, config.extra_s3_args)
+  return vim.list_extend(full_cmd, extra)
 end
 
 ---@param url string

lua/oil/adapters/ssh.lua

@@ -21,9 +21,21 @@ local FIELD_META = constants.FIELD_META
 ---@field port nil|integer
 ---@field path string
 
+---@param hosts string[]
 ---@param args string[]
-local function scp(args, ...)
+local function scp(hosts, args, ...)
-  local cmd = vim.list_extend({ 'scp', '-C' }, config.extra_scp_args)
+  local extra = vim.deepcopy(config.extra_scp_args)
+  local seen = {}
+  for _, host in ipairs(hosts) do
+    if not seen[host] then
+      seen[host] = true
+      local host_cfg = config.ssh_hosts[host]
+      if host_cfg and host_cfg.extra_scp_args then
+        vim.list_extend(extra, host_cfg.extra_scp_args)
+      end
+    end
+  end
+  local cmd = vim.list_extend({ 'scp', '-C' }, extra)
   vim.list_extend(cmd, args)
   shell.run(cmd, ...)
 end
@@ -320,12 +332,16 @@ M.perform_action = function(action, cb)
       local src_conn = get_connection(action.src_url)
       local dest_conn = get_connection(action.dest_url)
       if src_conn ~= dest_conn then
-        scp({ '-r', url_to_scp(src_res), url_to_scp(dest_res) }, function(err)
+        scp(
-          if err then
+          { src_res.host, dest_res.host },
-            return cb(err)
+          { '-r', url_to_scp(src_res), url_to_scp(dest_res) },
+          function(err)
+            if err then
+              return cb(err)
+            end
+            src_conn:rm(src_res.path, cb)
           end
-          src_conn:rm(src_res.path, cb)
+        )
-        end)
       else
         src_conn:mv(src_res.path, dest_res.path, cb)
       end
@@ -339,26 +355,31 @@ M.perform_action = function(action, cb)
       local src_res = M.parse_url(action.src_url)
       local dest_res = M.parse_url(action.dest_url)
       if not url_hosts_equal(src_res, dest_res) then
-        scp({ '-r', url_to_scp(src_res), url_to_scp(dest_res) }, cb)
+        scp(
+          { src_res.host, dest_res.host },
+          { '-r', url_to_scp(src_res), url_to_scp(dest_res) },
+          cb
+        )
       else
         local src_conn = get_connection(action.src_url)
         src_conn:cp(src_res.path, dest_res.path, cb)
       end
     else
-      local src_arg
-      local dest_arg
       if src_adapter == M then
-        src_arg = url_to_scp(M.parse_url(action.src_url))
+        local src_res = M.parse_url(action.src_url)
+        local src_arg = url_to_scp(src_res)
         local _, path = util.parse_url(action.dest_url)
         assert(path)
-        dest_arg = fs.posix_to_os_path(path)
+        local dest_arg = fs.posix_to_os_path(path)
+        scp({ src_res.host }, { '-r', src_arg, dest_arg }, cb)
       else
         local _, path = util.parse_url(action.src_url)
         assert(path)
-        src_arg = fs.posix_to_os_path(path)
+        local src_arg = fs.posix_to_os_path(path)
-        dest_arg = url_to_scp(M.parse_url(action.dest_url))
+        local dest_res = M.parse_url(action.dest_url)
+        local dest_arg = url_to_scp(dest_res)
+        scp({ dest_res.host }, { '-r', src_arg, dest_arg }, cb)
       end
-      scp({ '-r', src_arg, dest_arg }, cb)
     end
   else
     cb(string.format('Bad action type: %s', action.type))
@@ -384,7 +405,7 @@ M.read_file = function(bufnr)
   end
   local tmp_bufnr = vim.fn.bufadd(tmpfile)
 
-  scp({ scp_url, tmpfile }, function(err)
+  scp({ url.host }, { scp_url, tmpfile }, function(err)
     loading.set_loading(bufnr, false)
     vim.bo[bufnr].modifiable = true
     vim.cmd.doautocmd({ args = { 'BufReadPre', bufname }, mods = { silent = true } })
@@ -426,7 +447,7 @@ M.write_file = function(bufnr)
   vim.cmd.write({ args = { tmpfile }, bang = true, mods = { silent = true, noautocmd = true } })
   local tmp_bufnr = vim.fn.bufadd(tmpfile)
 
-  scp({ tmpfile, scp_url }, function(err)
+  scp({ url.host }, { tmpfile, scp_url }, function(err)
     vim.bo[bufnr].modifiable = true
     if err then
       vim.notify(string.format('Error writing file: %s', err), vim.log.levels.ERROR)

lua/oil/config.lua

@@ -118,6 +118,9 @@ local default_config = {
   extra_s3_args = {},
   -- Extra arguments to pass to curl for FTP operations
   extra_curl_args = {},
+  ssh_hosts = {},
+  s3_buckets = {},
+  ftp_hosts = {},
   -- EXPERIMENTAL support for performing file operations with git
   git = {
     -- Return true to automatically git add/mv/rm files
@@ -233,6 +236,15 @@ default_config.adapter_aliases = {}
 -- here we can get some performance wins
 default_config.view_options.highlight_filename = nil
 
+---@class (exact) oil.SshHostConfig
+---@field extra_scp_args? string[]
+
+---@class (exact) oil.S3BucketConfig
+---@field extra_s3_args? string[]
+
+---@class (exact) oil.FtpHostConfig
+---@field extra_curl_args? string[]
+
 ---@class oil.Config
 ---@field adapters table<string, string> Hidden from SetupOpts
 ---@field adapter_aliases table<string, string> Hidden from SetupOpts
@@ -259,6 +271,9 @@ default_config.view_options.highlight_filename = nil
 ---@field extra_scp_args string[]
 ---@field extra_s3_args string[]
 ---@field extra_curl_args string[]
+---@field ssh_hosts table<string, oil.SshHostConfig>
+---@field s3_buckets table<string, oil.S3BucketConfig>
+---@field ftp_hosts table<string, oil.FtpHostConfig>
 ---@field git oil.GitOptions
 ---@field float oil.FloatWindowConfig
 ---@field preview_win oil.PreviewWindowConfig
@@ -294,6 +309,9 @@ local M = {}
 ---@field extra_scp_args? string[] Extra arguments to pass to SCP when moving/copying files over SSH
 ---@field extra_s3_args? string[] Extra arguments to pass to aws s3 when moving/copying files using aws s3
 ---@field extra_curl_args? string[] Extra arguments to pass to curl for FTP operations
+---@field ssh_hosts? table<string, oil.SshHostConfig> Per-host SCP arg overrides
+---@field s3_buckets? table<string, oil.S3BucketConfig> Per-bucket S3 arg overrides
+---@field ftp_hosts? table<string, oil.FtpHostConfig> Per-host curl arg overrides
 ---@field git? oil.SetupGitOptions EXPERIMENTAL support for performing file operations with git
 ---@field float? oil.SetupFloatWindowConfig Configuration for the floating window in oil.open_float
 ---@field preview_win? oil.SetupPreviewWindowConfig Configuration for the file preview window

spec/per_host_args_spec.lua

@@ -0,0 +1,97 @@
+local config = require('oil.config')
+local test_util = require('spec.test_util')
+
+describe('per-host/bucket arg overrides', function()
+  after_each(function()
+    test_util.reset_editor()
+  end)
+
+  describe('ssh_hosts', function()
+    it('stores ssh_hosts from setup', function()
+      config.setup({ ssh_hosts = { ['myserver.com'] = { extra_scp_args = { '-O' } } } })
+      assert.are.equal('-O', config.ssh_hosts['myserver.com'].extra_scp_args[1])
+    end)
+
+    it('defaults to empty table when not set', function()
+      config.setup({})
+      assert.are.same({}, config.ssh_hosts)
+    end)
+
+    it('returns nil for unknown host', function()
+      config.setup({ ssh_hosts = { ['known.host'] = { extra_scp_args = { '-O' } } } })
+      assert.is_nil(config.ssh_hosts['unknown.host'])
+    end)
+  end)
+
+  describe('s3_buckets', function()
+    it('stores s3_buckets from setup', function()
+      config.setup({
+        s3_buckets = {
+          ['my-r2-bucket'] = { extra_s3_args = { '--endpoint-url', 'https://r2.example.com' } },
+        },
+      })
+      assert.are.equal('--endpoint-url', config.s3_buckets['my-r2-bucket'].extra_s3_args[1])
+      assert.are.equal('https://r2.example.com', config.s3_buckets['my-r2-bucket'].extra_s3_args[2])
+    end)
+
+    it('defaults to empty table when not set', function()
+      config.setup({})
+      assert.are.same({}, config.s3_buckets)
+    end)
+
+    it('returns nil for unknown bucket', function()
+      config.setup({
+        s3_buckets = { ['known-bucket'] = { extra_s3_args = { '--no-sign-request' } } },
+      })
+      assert.is_nil(config.s3_buckets['unknown-bucket'])
+    end)
+  end)
+
+  describe('ftp_hosts', function()
+    it('stores ftp_hosts from setup', function()
+      config.setup({ ftp_hosts = { ['ftp.internal.com'] = { extra_curl_args = { '--insecure' } } } })
+      assert.are.equal('--insecure', config.ftp_hosts['ftp.internal.com'].extra_curl_args[1])
+    end)
+
+    it('defaults to empty table when not set', function()
+      config.setup({})
+      assert.are.same({}, config.ftp_hosts)
+    end)
+
+    it('returns nil for unknown host', function()
+      config.setup({ ftp_hosts = { ['known.host'] = { extra_curl_args = { '--insecure' } } } })
+      assert.is_nil(config.ftp_hosts['unknown.host'])
+    end)
+
+    it('reflects --insecure in per-host curl args', function()
+      config.setup({ ftp_hosts = { ['ftp.internal.com'] = { extra_curl_args = { '--insecure' } } } })
+      local host_cfg = config.ftp_hosts['ftp.internal.com']
+      assert.is_truthy(vim.tbl_contains(host_cfg.extra_curl_args, '--insecure'))
+    end)
+  end)
+
+  describe('merge semantics', function()
+    it('per-host ssh args supplement global args', function()
+      config.setup({
+        extra_scp_args = { '-C' },
+        ssh_hosts = { ['myserver.com'] = { extra_scp_args = { '-O' } } },
+      })
+      assert.are.same({ '-C' }, config.extra_scp_args)
+      assert.are.same({ '-O' }, config.ssh_hosts['myserver.com'].extra_scp_args)
+    end)
+
+    it('per-bucket s3 args supplement global args', function()
+      config.setup({
+        extra_s3_args = { '--sse', 'aws:kms' },
+        s3_buckets = {
+          ['special-bucket'] = { extra_s3_args = { '--endpoint-url', 'https://...' } },
+        },
+      })
+      assert.are.same({ '--sse', 'aws:kms' }, config.extra_s3_args)
+      assert.are.same(
+        { '--endpoint-url', 'https://...' },
+        config.s3_buckets['special-bucket'].extra_s3_args
+      )
+    end)
+  end)
+end)