On empty buffers, when editing the first line, the line is buffered, causing offset to be < 0. While the buffer is not actually empty, the buffered line has not been flushed (and should not be) yet, so the call is valid but an edge case.
This caused segfaults when calling win_findbuf in an `on_detach`
callback, when the callback was triggered when closing the last window
containing the buffer.
Can be reproduced with a script like this:
-- in some lua file
vim.fn.timer_start(10, function() error("uh....") end)
-- will cause neovim to crash with the following error.
PANIC: unprotected error in call to Lua API
(nlua_CFunction_func_call failed.)
After this, it will instead print the error message
from the top of the stack, like so.
tmp/error_nvim.lua:10: uh...
Also added an example test. Previously this test
caused the embedded nvim to panic.
vim-patch:8.2.1054: not so easy to pass a lua function to Vim
vim-patch:8.2.1084: Lua: registering function has useless code
I think I have also opened up the possibility for people to use these
callbacks elsewhere, since I've added a new struct that we should be
able to use.
Also, this should allow us to determine what the state of a list is in
Lua or a dictionary in Lua, since we now can track the luaref as we go.
* Change uri_to_fname to not convert non-file URIs
A URI with a scheme other than file doesn't have a local file path.
* fixup! Change uri_to_fname to not convert non-file URIs
* fixup! fixup! Change uri_to_fname to not convert non-file URIs
* add lua function to highlight yanked region
* extract namespace, better naming, default values
* add default for event argument
* free timer
* factor out mark to position calculation
* d'oh
* make sure timer stops before callback (cf. luv example)
* factor out timer, more documentation
* fixup
* validate function argument for schedule
* fix block selection past eol
* correct handling of multibyte characters
* move arguments around, some cleanup
* move utility functions to vim.lua
* use anonymous namespaces, avoid local api
* rename function
* add test for schedule_fn
* fix indent
* turn hl-yank into proper (hightlight) module
* factor out position-to-region function
mark extraction now part of highlight.on_yank
* rename schedule_fn to defer_fn
* add test for vim.region
* todo: handle double-width characters
* remove debug printout
* do not shadow arguments
* defer also callable table
* whitespace change
* move highlight to vim/highlight.lua
* add documentation
* add @return documentation
* test: add check before vim.defer fires
* doc: fixup
