fix(vim.system): let on_exit handle cleanup after kill

Fixes #25000

runtime/lua/vim/_system.lua

@@ -18,6 +18,7 @@ local uv = vim.uv
 --- @field stderr? string
 
 --- @class SystemState
+--- @field cmd string[]
 --- @field handle? uv.uv_process_t
 --- @field timer?  uv.uv_timer_t
 --- @field pid? integer
@@ -63,11 +64,9 @@ local function new_systemobj(state)
   }, { __index = SystemObj })
 end
 
---- @param signal integer
+--- @param signal integer|string
 function SystemObj:kill(signal)
-  local state = self._state
-  state.handle:kill(signal)
-  close_handles(state)
+  self._state.handle:kill(signal)
 end
 
 local MAX_TIMEOUT = 2 ^ 31
@@ -159,7 +158,7 @@ end
 
 --- @return table<string,string>
 local function base_env()
-  local env = vim.fn.environ()
+  local env = vim.fn.environ() --- @type table<string,string>
   env['NVIM'] = vim.v.servername
   env['NVIM_LISTEN_ADDRESS'] = nil
   return env
@@ -212,7 +211,7 @@ end
 local M = {}
 
 --- @param cmd string
---- @param opts uv.aliases.spawn_options
+--- @param opts uv.spawn.options
 --- @param on_exit fun(code: integer, signal: integer)
 --- @param on_error fun()
 --- @return uv.uv_process_t, integer

test/functional/lua/system_spec.lua

@@ -54,4 +54,28 @@ describe('vim.system', function()
     end)
   end
 
+  it('kill processes', function()
+    exec_lua([[
+      local signal
+      local cmd = vim.system({ 'cat', '-' }, { stdin = true }, function(r)
+        signal = r.signal
+      end) -- run forever
+
+      cmd:kill('sigint')
+
+      -- wait for the process not to exist
+      local done = vim.wait(2000, function()
+        return signal ~= nil
+      end)
+
+      assert(done, 'process did not exit')
+
+      -- Check the process is no longer running
+      vim.fn.systemlist({'ps', 'p', tostring(cmd.pid)})
+      assert(vim.v.shell_error == 1, 'dwqdqd '..vim.v.shell_error)
+
+      assert(signal == 2)
+    ]])
+  end)
+
 end)