fix(stream): do not close handle if it is already closing (#26537)

uv_close asserts that a handle is not already closing. We can guard
against this assertion failure by manually checking the handle's closing
status ourselves.

src/nvim/event/stream.c

@@ -128,15 +128,22 @@ void stream_may_close(Stream *stream)
 void stream_close_handle(Stream *stream)
   FUNC_ATTR_NONNULL_ALL
 {
+  uv_handle_t *handle = NULL;
   if (stream->uvstream) {
     if (uv_stream_get_write_queue_size(stream->uvstream) > 0) {
       WLOG("closed Stream (%p) with %zu unwritten bytes",
            (void *)stream,
            uv_stream_get_write_queue_size(stream->uvstream));
     }
-    uv_close((uv_handle_t *)stream->uvstream, close_cb);
+    handle = (uv_handle_t *)stream->uvstream;
   } else {
-    uv_close((uv_handle_t *)&stream->uv.idle, close_cb);
+    handle = (uv_handle_t *)&stream->uv.idle;
+  }
+
+  assert(handle != NULL);
+
+  if (!uv_is_closing(handle)) {
+    uv_close(handle, close_cb);
   }
 }
 

test/functional/core/job_spec.lua

@@ -1,4 +1,5 @@
 local helpers = require('test.functional.helpers')(after_each)
+local thelpers = require('test.functional.terminal.helpers')
 local clear, eq, eval, exc_exec, feed_command, feed, insert, neq, next_msg, nvim,
   testprg, ok, source, write_file, mkdir, rmdir = helpers.clear,
   helpers.eq, helpers.eval, helpers.exc_exec, helpers.feed_command, helpers.feed,
@@ -1140,6 +1141,31 @@ describe('jobs', function()
       command('call jobstop(' .. other_jobid .. ')')
     end)
   end)
+
+  it('does not close the same handle twice on exit #25086', function()
+    local filename = string.format('%s.lua', helpers.tmpname())
+    write_file(filename, [[
+      vim.api.nvim_create_autocmd('VimLeavePre', {
+        callback = function()
+          local id = vim.fn.jobstart('sleep 0')
+          vim.fn.jobwait({id})
+        end,
+      })
+    ]])
+
+    local screen = thelpers.setup_child_nvim({
+      '-i', 'NONE',
+      '-u', filename,
+      '+q'
+    })
+
+    screen:expect{grid=[[
+                                                        |
+      [Process exited 0]{1: }                               |
+                                                        |*4
+      {3:-- TERMINAL --}                                    |
+    ]]}
+  end)
 end)
 
 describe("pty process teardown", function()