jobs: ensure calling jobclose() on a pty job sends SIGHUP. Closes #5619

runtime/doc/eval.txt

@@ -4411,7 +4411,8 @@ jobclose({job}[, {stream}])				{Nvim} *jobclose()*
 		Close {job}'s {stream}, which can be one of "stdin", "stdout",
 		"stderr" or "rpc" (closes the rpc channel for a job started
 		with the "rpc" option.) If {stream} is omitted, all streams
-		are closed.
+		are closed. If the job is a pty job, this will then close the
+		pty master, sending SIGHUP to the job process.
 
 jobpid({job})						{Nvim} *jobpid()*
 		Return the pid (process id) of {job}.

src/nvim/eval.c

@@ -11459,6 +11459,9 @@ static void f_jobclose(typval_T *argvars, typval_T *rettv, FunPtr fptr)
       process_close_err(proc);
     } else {
       process_close_streams(proc);
+      if (proc->type == kProcessTypePty) {
+        pty_process_close_master(&data->proc.pty);
+      }
     }
   }
 }

test/functional/core/job_spec.lua

@@ -480,6 +480,12 @@ describe('jobs', function()
       nvim('command', 'call jobresize(j, 10, 40)')
       eq('rows: 40, cols: 10', next_chunk())
     end)
+
+    it('calling jobclose()', function()
+      -- this should send SIGHUP to the process
+      nvim('command', 'call jobclose(j)')
+      eq({'notification', 'exit', {0, 1}}, next_msg())
+    end)
   end)
 end)