fix(channel): throw error if sending to internal channel w/o terminal

Prevent SIGABRT when sending to a channel created by nvim_open_term()
after the associated terminal has been deleted.

2 files changed, 15 insertions, 1 deletions

diff --git a/src/nvim/channel.c b/src/nvim/channel.c
index 0eae87c1f8..9662f6205f 100644
--- a/src/nvim/channel.c
+++ b/src/nvim/channel.c
@@ -535,7 +535,11 @@ size_t channel_send(uint64_t id, char *data, size_t len, bool data_owned, const
     goto retfree;
   }
 
-  if (chan->streamtype == kChannelStreamInternal && chan->term) {
+  if (chan->streamtype == kChannelStreamInternal) {
+    if (!chan->term) {
+      *error = _("Can't send data to closed stream");
+      goto retfree;
+    }
     terminal_receive(chan->term, data, len);
     written = len;
     goto retfree;
diff --git a/test/functional/core/channels_spec.lua b/test/functional/core/channels_spec.lua
index 93dec9fb35..e5ded6428f 100644
--- a/test/functional/core/channels_spec.lua
+++ b/test/functional/core/channels_spec.lua
@@ -281,4 +281,14 @@ describe('channels', function()
     -- works correctly with no output
     eq({"notification", "exit", {id, 1, {''}}}, next_msg())
   end)
+
+  it('should throw error when writing to a channel associated with a deleted terminal', function()
+    source([[
+      let id = nvim_open_term(0, {})
+      bdelete!
+      let v:errmsg = ''
+      silent! call chansend(id, 'test')
+    ]])
+    eq("Can't send data to closed stream", eval('v:errmsg'))
+  end)
 end)