4 files changed, 25 insertions, 20 deletions

diff --git a/src/nvim/api/private/helpers.c b/src/nvim/api/private/helpers.c
index 1115faaeaf..12a4279dd7 100644
--- a/src/nvim/api/private/helpers.c
+++ b/src/nvim/api/private/helpers.c
@@ -47,13 +47,15 @@ typedef struct {
 /// @param[out]  tstate  Location where try state should be saved.
 void try_enter(TryState *const tstate)
 {
+  // TODO(ZyX-I): Check whether try_enter()/try_leave() may use
+  //              enter_cleanup()/leave_cleanup(). Or
+  //              save_dbg_stuff()/restore_dbg_stuff().
   *tstate = (TryState) {
     .current_exception = current_exception,
     .msg_list = (const struct msglist *const *)msg_list,
     .private_msg_list = NULL,
     .trylevel = trylevel,
     .got_int = got_int,
-    .did_throw = did_throw,
     .need_rethrow = need_rethrow,
     .did_emsg = did_emsg,
   };
@@ -61,7 +63,6 @@ void try_enter(TryState *const tstate)
   current_exception = NULL;
   trylevel = 1;
   got_int = false;
-  did_throw = false;
   need_rethrow = false;
   did_emsg = false;
 }
@@ -82,7 +83,6 @@ bool try_leave(const TryState *const tstate, Error *const err)
   assert(trylevel == 0);
   assert(!need_rethrow);
   assert(!got_int);
-  assert(!did_throw);
   assert(!did_emsg);
   assert(msg_list == &tstate->private_msg_list);
   assert(*msg_list == NULL);
@@ -91,7 +91,6 @@ bool try_leave(const TryState *const tstate, Error *const err)
   current_exception = tstate->current_exception;
   trylevel = tstate->trylevel;
   got_int = tstate->got_int;
-  did_throw = tstate->did_throw;
   need_rethrow = tstate->need_rethrow;
   did_emsg = tstate->did_emsg;
   return ret;
@@ -127,7 +126,7 @@ bool try_end(Error *err)
   did_emsg = false;
 
   if (got_int) {
-    if (did_throw) {
+    if (current_exception) {
       // If we got an interrupt, discard the current exception
       discard_current_exception();
     }
@@ -146,7 +145,7 @@ bool try_end(Error *err)
     if (should_free) {
       xfree(msg);
     }
-  } else if (did_throw) {
+  } else if (current_exception) {
     api_set_error(err, kErrorTypeException, "%s", current_exception->value);
     discard_current_exception();
   }
diff --git a/src/nvim/api/private/helpers.h b/src/nvim/api/private/helpers.h
index 87f334ac30..0634764f13 100644
--- a/src/nvim/api/private/helpers.h
+++ b/src/nvim/api/private/helpers.h
@@ -93,7 +93,6 @@ typedef struct {
   const struct msglist *const *msg_list;
   int trylevel;
   int got_int;
-  int did_throw;
   int need_rethrow;
   int did_emsg;
 } TryState;
diff --git a/src/nvim/api/ui.c b/src/nvim/api/ui.c
index 4870c3fb8a..4cd2657561 100644
--- a/src/nvim/api/ui.c
+++ b/src/nvim/api/ui.c
@@ -56,7 +56,8 @@ void nvim_ui_attach(uint64_t channel_id, Integer width, Integer height,
   FUNC_API_SINCE(1) FUNC_API_REMOTE_ONLY
 {
   if (pmap_has(uint64_t)(connected_uis, channel_id)) {
-    api_set_error(err, kErrorTypeException, "UI already attached for channel");
+    api_set_error(err, kErrorTypeException,
+                  "UI already attached to channel: %" PRId64, channel_id);
     return;
   }
 
@@ -130,7 +131,8 @@ void nvim_ui_detach(uint64_t channel_id, Error *err)
   FUNC_API_SINCE(1) FUNC_API_REMOTE_ONLY
 {
   if (!pmap_has(uint64_t)(connected_uis, channel_id)) {
-    api_set_error(err, kErrorTypeException, "UI is not attached for channel");
+    api_set_error(err, kErrorTypeException,
+                  "UI not attached to channel: %" PRId64, channel_id);
     return;
   }
   remote_ui_disconnect(channel_id);
@@ -142,7 +144,8 @@ void nvim_ui_try_resize(uint64_t channel_id, Integer width,
   FUNC_API_SINCE(1) FUNC_API_REMOTE_ONLY
 {
   if (!pmap_has(uint64_t)(connected_uis, channel_id)) {
-    api_set_error(err, kErrorTypeException, "UI is not attached for channel");
+    api_set_error(err, kErrorTypeException,
+                  "UI not attached to channel: %" PRId64, channel_id);
     return;
   }
 
@@ -163,7 +166,8 @@ void nvim_ui_set_option(uint64_t channel_id, String name,
   FUNC_API_SINCE(1) FUNC_API_REMOTE_ONLY
 {
   if (!pmap_has(uint64_t)(connected_uis, channel_id)) {
-    api_set_error(error, kErrorTypeException, "UI is not attached for channel");
+    api_set_error(error, kErrorTypeException,
+                  "UI not attached to channel: %" PRId64, channel_id);
     return;
   }
   UI *ui = pmap_get(uint64_t)(connected_uis, channel_id);
@@ -209,7 +213,8 @@ static void ui_set_option(UI *ui, String name, Object value, Error *error)
     return;
   }
 
-  api_set_error(error, kErrorTypeValidation, "No such ui option");
+  api_set_error(error, kErrorTypeValidation, "No such UI option: %s",
+                name.data);
 #undef UI_EXT_OPTION
 }
 
diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index 962081cc23..07ec6e8c27 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -239,15 +239,17 @@ String nvim_command_output(String command, Error *err)
   }
 
   if (capture_local.ga_len > 1) {
-    // redir always(?) prepends a newline; remove it.
-    char *s = capture_local.ga_data;
-    assert(s[0] == '\n');
-    memmove(s, s + 1, (size_t)capture_local.ga_len);
-    s[capture_local.ga_len - 1] = '\0';
-    return (String) {  // Caller will free the memory.
-      .data = s,
-      .size = (size_t)(capture_local.ga_len - 1),
+    String s = (String){
+      .data = capture_local.ga_data,
+      .size = (size_t)capture_local.ga_len,
     };
+    // redir usually (except :echon) prepends a newline.
+    if (s.data[0] == '\n') {
+      memmove(s.data, s.data + 1, s.size);
+      s.data[s.size - 1] = '\0';
+      s.size = s.size - 1;
+    }
+    return s;  // Caller will free the memory.
   }
 
 theend: