Merge #5502 from justinmk/error-write-to-bg-process

system('foo &', 'bar'): Show error, don't crash.

2 files changed, 12 insertions, 2 deletions

diff --git a/src/nvim/event/rstream.c b/src/nvim/event/rstream.c
index 5126dfd84e..92efc9fa2e 100644
--- a/src/nvim/event/rstream.c
+++ b/src/nvim/event/rstream.c
@@ -112,8 +112,8 @@ static void read_cb(uv_stream_t *uvstream, ssize_t cnt, const uv_buf_t *buf)
         // to `alloc_cb` will return the same unused pointer(`rbuffer_produced`
         // won't be called)
         && cnt != 0) {
-      DLOG("Closing Stream(%p) because of %s(%zd)", stream,
-           uv_strerror((int)cnt), cnt);
+      DLOG("Closing Stream (%p): %s (%s)", stream,
+           uv_err_name((int)cnt), os_strerror((int)cnt));
       // Read error or EOF, either way stop the stream and invoke the callback
       // with eof == true
       uv_read_stop(uvstream);
diff --git a/src/nvim/os/shell.c b/src/nvim/os/shell.c
index e9a3dcbff8..18ee008d66 100644
--- a/src/nvim/os/shell.c
+++ b/src/nvim/os/shell.c
@@ -545,6 +545,16 @@ static size_t write_output(char *output, size_t remaining, bool to_buffer,
 
 static void shell_write_cb(Stream *stream, void *data, int status)
 {
+  if (status) {
+    // Can happen if system() tries to send input to a shell command that was
+    // backgrounded (:call system("cat - &", "foo")). #3529 #5241
+    EMSG2(_("E5677: Error writing input to shell-command: %s"),
+          uv_err_name(status));
+  }
+  if (stream->closed) {  // Process may have exited before this write.
+    ELOG("stream was already closed");
+    return;
+  }
   stream_close(stream, NULL, NULL);
 }