:ls : show "R", "F" for terminal-jobs #10370

This matches Vim behavior. From `:help :ls` :

    R    a terminal buffer with a running job
    F    a terminal buffer with a finished job
    ?    a terminal buffer without a job: `:terminal NONE`

TODO: implement `:terminal NONE`.

ref #10349

src/nvim/buffer.c

@@ -29,6 +29,7 @@
 #include "nvim/api/vim.h"
 #include "nvim/ascii.h"
 #include "nvim/assert.h"
+#include "nvim/channel.h"
 #include "nvim/vim.h"
 #include "nvim/buffer.h"
 #include "nvim/charset.h"
@@ -2608,9 +2609,10 @@ void buflist_list(exarg_T *eap)
     const int changed_char = (buf->b_flags & BF_READERR)
       ? 'x'
       : (bufIsChanged(buf) ? '+' : ' ');
-    const int ro_char = !MODIFIABLE(buf)
-      ? '-'
-      : (buf->b_p_ro ? '=' : ' ');
+    int ro_char = !MODIFIABLE(buf) ? '-' : (buf->b_p_ro ? '=' : ' ');
+    if (buf->terminal) {
+      ro_char = channel_job_running((uint64_t)buf->b_p_channel) ? 'R' : 'F';
+    }
 
     msg_putchar('\n');
     len = vim_snprintf(

src/nvim/channel.c

@@ -762,6 +762,14 @@ static void set_info_event(void **argv)
   channel_decref(chan);
 }
 
+bool channel_job_running(uint64_t id)
+{
+  Channel *chan = find_channel(id);
+  return (chan
+          && chan->streamtype == kChannelStreamProc
+          && !process_is_stopped(&chan->stream.proc));
+}
+
 Dictionary channel_info(uint64_t id)
 {
   Channel *chan = find_channel(id);

src/nvim/event/process.h

@@ -56,7 +56,8 @@ static inline Process process_init(Loop *loop, ProcessType type, void *data)
 
 static inline bool process_is_stopped(Process *proc)
 {
-  return proc->stopped_time != 0;
+  bool exited = (proc->status >= 0);
+  return exited || (proc->stopped_time != 0);
 }
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS