API: TRY_WRAP() for "abort-causing non-exception errors"

- Introduce TRY_WRAP() until we have an *architectural* solution.
  - TODO: bfredl idea: prepare error-handling at "top level" (nv_event).
- nvim_paste(): Revert luaeval() hack (see parent commit).
  - With TRY_WRAP() in nvim_put(), 'nomodifiable' error now correctly
    "bubbles up".

src/nvim/api/vim.c

@@ -54,6 +54,20 @@
 # include "api/vim.c.generated.h"
 #endif
 
+// `msg_list` controls the collection of abort-causing non-exception errors,
+// which would otherwise be ignored.  This pattern is from do_cmdline().
+//
+// TODO(bfredl): prepare error-handling at "top level" (nv_event).
+#define TRY_WRAP(code) \
+  do { \
+    struct msglist **saved_msg_list = msg_list; \
+    struct msglist *private_msg_list; \
+    msg_list = &private_msg_list; \
+    private_msg_list = NULL; \
+    code \
+    msg_list = saved_msg_list;  /* Restore the exception context. */ \
+  } while (0)
+
 void api_vim_init(void)
   FUNC_API_NOEXPORT
 {
@@ -392,13 +406,7 @@ Object nvim_eval(String expr, Error *err)
   static int recursive = 0;  // recursion depth
   Object rv = OBJECT_INIT;
 
-  // `msg_list` controls the collection of abort-causing non-exception errors,
+  TRY_WRAP({
-  // which would otherwise be ignored.  This pattern is from do_cmdline().
-  struct msglist **saved_msg_list = msg_list;
-  struct msglist *private_msg_list;
-  msg_list = &private_msg_list;
-  private_msg_list = NULL;
-
   // Initialize `force_abort`  and `suppress_errthrow` at the top level.
   if (!recursive) {
     force_abort = false;
@@ -423,8 +431,8 @@ Object nvim_eval(String expr, Error *err)
   }
 
   tv_clear(&rettv);
-  msg_list = saved_msg_list;  // Restore the exception context.
   recursive--;
+  });
 
   return rv;
 }
@@ -474,13 +482,7 @@ static Object _call_function(String fn, Array args, dict_T *self, Error *err)
     }
   }
 
-  // `msg_list` controls the collection of abort-causing non-exception errors,
+  TRY_WRAP({
-  // which would otherwise be ignored.  This pattern is from do_cmdline().
-  struct msglist **saved_msg_list = msg_list;
-  struct msglist *private_msg_list;
-  msg_list = &private_msg_list;
-  private_msg_list = NULL;
-
   // Initialize `force_abort`  and `suppress_errthrow` at the top level.
   if (!recursive) {
     force_abort = false;
@@ -502,8 +504,8 @@ static Object _call_function(String fn, Array args, dict_T *self, Error *err)
     rv = vim_to_object(&rettv);
   }
   tv_clear(&rettv);
-  msg_list = saved_msg_list;  // Restore the exception context.
   recursive--;
+  });
 
 free_vim_args:
   while (i > 0) {
@@ -1238,7 +1240,6 @@ Boolean nvim_paste(String data, Integer phase, Error *err)
     return false;
   }
   Array args = ARRAY_DICT_INIT;
-  Array args2 = ARRAY_DICT_INIT;
   Object rv = OBJECT_INIT;
   if (phase == -1 || phase == 1) {  // Start of paste-stream.
     draining = false;
@@ -1249,9 +1250,8 @@ Boolean nvim_paste(String data, Integer phase, Error *err)
   Array lines = string_to_array(data);
   ADD(args, ARRAY_OBJ(lines));
   ADD(args, INTEGER_OBJ(phase));
-  ADD(args2, STRING_OBJ(cstr_to_string("vim.paste(_A[1], _A[2])")));
+  rv = nvim_execute_lua(STATIC_CSTR_AS_STRING("return vim.paste(...)"), args,
-  ADD(args2, ARRAY_OBJ(args2));
+                        err);
-  rv = nvim_call_function(STATIC_CSTR_AS_STRING("luaeval"), args2, err);
   if (ERROR_SET(err)) {
     draining = true;
     goto theend;
@@ -1278,7 +1278,8 @@ Boolean nvim_paste(String data, Integer phase, Error *err)
     AppendCharToRedobuff(ESC);  // Dot-repeat.
   }
 theend:
-  api_free_array(args2);
+  api_free_object(rv);
+  api_free_array(args);
   if (cancel || phase == -1 || phase == 3) {  // End of paste-stream.
     draining = false;
     // XXX: Tickle main loop to ensure cursor is updated.
@@ -1310,10 +1311,6 @@ void nvim_put(ArrayOf(String) lines, String type, Boolean after,
     api_set_error(err, kErrorTypeValidation, "Invalid type: '%s'", type.data);
     goto cleanup;
   }
-  if (!MODIFIABLE(curbuf)) {
-    api_set_error(err, kErrorTypeException, "Buffer is not 'modifiable'");
-    goto cleanup;
-  }
   if (lines.size == 0) {
     goto cleanup;  // Nothing to do.
   }
@@ -1331,13 +1328,15 @@ void nvim_put(ArrayOf(String) lines, String type, Boolean after,
 
   finish_yankreg_from_object(reg, false);
 
-  bool VIsual_was_active = VIsual_active;
+  TRY_WRAP({
-  msg_silent++;  // Avoid "N more lines" message.
+    try_start();
-  do_put(0, reg,
+    bool VIsual_was_active = VIsual_active;
-         after ? FORWARD : BACKWARD, 1,
+    msg_silent++;  // Avoid "N more lines" message.
-         follow ? PUT_CURSEND : 0);
+    do_put(0, reg, after ? FORWARD : BACKWARD, 1, follow ? PUT_CURSEND : 0);
-  msg_silent--;
+    msg_silent--;
-  VIsual_active = VIsual_was_active;
+    VIsual_active = VIsual_was_active;
+    try_end(err);
+  });
 
 cleanup:
   free_register(reg);

test/functional/api/vim_spec.lua

@@ -411,7 +411,7 @@ describe('API', function()
     end)
     it("fails if 'nomodifiable'", function()
       command('set nomodifiable')
-      expect_err([[Buffer is not 'modifiable']], request,
+      expect_err([[Vim:E21: Cannot make changes, 'modifiable' is off]], request,
         'nvim_put', {'a','b'}, 'l', true, true)
     end)
     it('inserts text', function()

test/functional/terminal/tui_spec.lua

@@ -185,6 +185,7 @@ describe('TUI', function()
       {3:-- TERMINAL --}                                    |
     ]])
     feed_data('pasted from terminal')
+    expect_child_buf_lines({'"pasted from terminal"'})
     screen:expect([[
       "pasted from terminal{1:"}                            |
       {4:~                                                 }|
@@ -196,6 +197,7 @@ describe('TUI', function()
     ]])
     feed_data('\027[201~')  -- End paste.
     feed_data('\027\000')   -- ESC: go to Normal mode.
+    wait_for_mode('n')
     screen:expect([[
       "pasted from termina{1:l}"                            |
       {4:~                                                 }|
@@ -207,6 +209,8 @@ describe('TUI', function()
     ]])
     -- Dot-repeat/redo.
     feed_data('2.')
+    expect_child_buf_lines(
+      {'"pasted from terminapasted from terminalpasted from terminall"'})
     screen:expect([[
       "pasted from terminapasted from terminalpasted fro|
       m termina{1:l}l"                                      |
@@ -341,18 +345,10 @@ describe('TUI', function()
                                                         |
       {3:-- TERMINAL --}                                    |
     ]]}
-    wait_for_mode('n')
     -- Start pasting...
     feed_data('\027[200~line 1\nline 2\n')
-    screen:expect{grid=[[
+    wait_for_mode('n')
-      foo                                               |
+    screen:expect{any='paste: Error executing lua'}
-                                                        |
-      {4:~                                                 }|
-      {5:                                                  }|
-      {8:paste: Vim:E5108: Error while calling lua chunk fo}|
-      {10:Press ENTER or type command to continue}{1: }          |
-      {3:-- TERMINAL --}                                    |
-    ]]}
     -- Remaining chunks are discarded after vim.paste() failure.
     feed_data('line 3\nline 4\n')
     feed_data('line 5\nline 6\n')
@@ -402,15 +398,7 @@ describe('TUI', function()
   it("paste: 'nomodifiable' buffer", function()
     child_session:request('nvim_command', 'set nomodifiable')
     feed_data('\027[200~fail 1\nfail 2\n\027[201~')
-    screen:expect{grid=[[
+    screen:expect{any='Vim:E21'}
-                                                        |
-      {5:                                                  }|
-      {8:paste: Vim:E5108: Error while calling lua chunk fo}|
-      {8:r luaeval(): [string "-- Nvim-Lua stdlib: the `vim}|
-      {8:` module (:help l..."]:193: Buffer is not 'modifia}|
-      {10:Press ENTER or type command to continue}{1: }          |
-      {3:-- TERMINAL --}                                    |
-    ]]}
     feed_data('\n')  -- <Enter>
     child_session:request('nvim_command', 'set modifiable')
     feed_data('\027[200~success 1\nsuccess 2\n\027[201~')