4 files changed, 53 insertions, 12 deletions

diff --git a/src/nvim/event/libuv_process.c b/src/nvim/event/libuv_process.c
index 63efee59a8..13517d3df1 100644
--- a/src/nvim/event/libuv_process.c
+++ b/src/nvim/event/libuv_process.c
@@ -41,7 +41,7 @@ int libuv_process_spawn(LibuvProcess *uvproc)
 #endif
   uvproc->uvopts.exit_cb = exit_cb;
   uvproc->uvopts.cwd = proc->cwd;
-  uvproc->uvopts.env = NULL;  // Inherits the parent (nvim) env.
+  uvproc->uvopts.env = proc->env;
   uvproc->uvopts.stdio = uvproc->uvstdio;
   uvproc->uvopts.stdio_count = 3;
   uvproc->uvstdio[0].flags = UV_IGNORE;
@@ -52,7 +52,7 @@ int libuv_process_spawn(LibuvProcess *uvproc)
   if (!proc->in.closed) {
     uvproc->uvstdio[0].flags = UV_CREATE_PIPE | UV_READABLE_PIPE;
 #ifdef WIN32
-    uvproc->uvstdio[0].flags |= UV_OVERLAPPED_PIPE;
+    uvproc->uvstdio[0].flags |= proc->overlapped ? UV_OVERLAPPED_PIPE : 0;
 #endif
     uvproc->uvstdio[0].data.stream = STRUCT_CAST(uv_stream_t,
                                                  &proc->in.uv.pipe);
@@ -61,8 +61,9 @@ int libuv_process_spawn(LibuvProcess *uvproc)
   if (!proc->out.closed) {
     uvproc->uvstdio[1].flags = UV_CREATE_PIPE | UV_WRITABLE_PIPE;
 #ifdef WIN32
-    // pipe must be readable for IOCP to work.
-    uvproc->uvstdio[1].flags |= UV_READABLE_PIPE | UV_OVERLAPPED_PIPE;
+    // pipe must be readable for IOCP to work on Windows.
+    uvproc->uvstdio[1].flags |= proc->overlapped ?
+      (UV_READABLE_PIPE | UV_OVERLAPPED_PIPE) : 0;
 #endif
     uvproc->uvstdio[1].data.stream = STRUCT_CAST(uv_stream_t,
                                                  &proc->out.uv.pipe);
diff --git a/src/nvim/event/loop.c b/src/nvim/event/loop.c
index a01bbc9888..e341513ae1 100644
--- a/src/nvim/event/loop.c
+++ b/src/nvim/event/loop.c
@@ -116,6 +116,20 @@ void loop_on_put(MultiQueue *queue, void *data)
   uv_stop(&loop->uv);
 }
 
+#if !defined(EXITFREE)
+static void loop_walk_cb(uv_handle_t *handle, void *arg)
+{
+  if (!uv_is_closing(handle)) {
+    uv_close(handle, NULL);
+  }
+}
+#endif
+
+/// Closes `loop` and its handles, and frees its structures.
+///
+/// @param loop  Loop to destroy
+/// @param wait  Wait briefly for handles to deref
+///
 /// @returns false if the loop could not be closed gracefully
 bool loop_close(Loop *loop, bool wait)
 {
@@ -126,18 +140,34 @@ bool loop_close(Loop *loop, bool wait)
   uv_close((uv_handle_t *)&loop->poll_timer, timer_close_cb);
   uv_close((uv_handle_t *)&loop->async, NULL);
   uint64_t start = wait ? os_hrtime() : 0;
+  bool didstop = false;
   while (true) {
-    uv_run(&loop->uv, wait ? UV_RUN_DEFAULT : UV_RUN_NOWAIT);
-    if (!uv_loop_close(&loop->uv) || !wait) {
+    // Run the loop to tickle close-callbacks (which should then free memory).
+    // Use UV_RUN_NOWAIT to avoid a hang. #11820
+    uv_run(&loop->uv, didstop ? UV_RUN_DEFAULT : UV_RUN_NOWAIT);
+    if ((uv_loop_close(&loop->uv) != UV_EBUSY) || !wait) {
       break;
     }
-    if (os_hrtime() - start >= 2 * 1000000000) {
+    uint64_t elapsed_s = (os_hrtime() - start) / 1000000000;  // seconds
+    if (elapsed_s >= 2) {
       // Some libuv resource was not correctly deref'd. Log and bail.
       rv = false;
       ELOG("uv_loop_close() hang?");
       log_uv_handles(&loop->uv);
       break;
     }
+#if defined(EXITFREE)
+    (void)didstop;
+#else
+    if (!didstop) {
+      // Loop won’t block for I/O after this.
+      uv_stop(&loop->uv);
+      // XXX: Close all (lua/luv!) handles. But loop_walk_cb() does not call
+      // resource-specific close-callbacks, so this leaks memory...
+      uv_walk(&loop->uv, loop_walk_cb, NULL);
+      didstop = true;
+    }
+#endif
   }
   multiqueue_free(loop->fast_events);
   multiqueue_free(loop->thread_events);
@@ -162,10 +192,6 @@ size_t loop_size(Loop *loop)
   return rv;
 }
 
-void loop_dummy_event(void **argv)
-{
-}
-
 static void async_cb(uv_async_t *handle)
 {
   Loop *l = handle->loop->data;
diff --git a/src/nvim/event/process.h b/src/nvim/event/process.h
index ef9d953ab7..84e81238e9 100644
--- a/src/nvim/event/process.h
+++ b/src/nvim/event/process.h
@@ -23,10 +23,11 @@ struct process {
   uint64_t stopped_time;  // process_stop() timestamp
   const char *cwd;
   char **argv;
+  char **env;
   Stream in, out, err;
   process_exit_cb cb;
   internal_process_cb internal_exit_cb, internal_close_cb;
-  bool closed, detach;
+  bool closed, detach, overlapped;
   MultiQueue *events;
 };
 
diff --git a/src/nvim/event/stream.c b/src/nvim/event/stream.c
index d1a53fa4b6..1e9e530a42 100644
--- a/src/nvim/event/stream.c
+++ b/src/nvim/event/stream.c
@@ -11,11 +11,19 @@
 #include "nvim/rbuffer.h"
 #include "nvim/macros.h"
 #include "nvim/event/stream.h"
+#ifdef WIN32
+# include "nvim/os/os_win_console.h"
+#endif
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "event/stream.c.generated.h"
 #endif
 
+// For compatbility with libuv < 1.19.0 (tested on 1.18.0)
+#if UV_VERSION_MINOR < 19
+#define uv_stream_get_write_queue_size(stream) stream->write_queue_size
+#endif
+
 /// Sets the stream associated with `fd` to "blocking" mode.
 ///
 /// @return `0` on success, or libuv error code on failure.
@@ -57,6 +65,11 @@ void stream_init(Loop *loop, Stream *stream, int fd, uv_stream_t *uvstream)
       if (type == UV_TTY) {
         uv_tty_init(&loop->uv, &stream->uv.tty, fd, 0);
         uv_tty_set_mode(&stream->uv.tty, UV_TTY_MODE_RAW);
+        DWORD dwMode;
+        if (GetConsoleMode(stream->uv.tty.handle, &dwMode)) {
+          dwMode |= ENABLE_VIRTUAL_TERMINAL_INPUT;
+          SetConsoleMode(stream->uv.tty.handle, dwMode);
+        }
         stream->uvstream = STRUCT_CAST(uv_stream_t, &stream->uv.tty);
       } else {
 #endif