1 files changed, 40 insertions, 30 deletions

diff --git a/runtime/lua/vim/lsp/completion.lua b/runtime/lua/vim/lsp/completion.lua
index 71ea2df100..92bc110a97 100644
--- a/runtime/lua/vim/lsp/completion.lua
+++ b/runtime/lua/vim/lsp/completion.lua
@@ -113,12 +113,11 @@ local function parse_snippet(input)
 end
 
 --- @param item lsp.CompletionItem
---- @param suffix? string
-local function apply_snippet(item, suffix)
+local function apply_snippet(item)
   if item.textEdit then
-    vim.snippet.expand(item.textEdit.newText .. suffix)
+    vim.snippet.expand(item.textEdit.newText)
   elseif item.insertText then
-    vim.snippet.expand(item.insertText .. suffix)
+    vim.snippet.expand(item.insertText)
   end
 end
 
@@ -221,6 +220,20 @@ local function get_doc(item)
   return ''
 end
 
+---@param value string
+---@param prefix string
+---@return boolean
+local function match_item_by_value(value, prefix)
+  if vim.o.completeopt:find('fuzzy') ~= nil then
+    return next(vim.fn.matchfuzzy({ value }, prefix)) ~= nil
+  end
+
+  if vim.o.ignorecase and (not vim.o.smartcase or not prefix:find('%u')) then
+    return vim.startswith(value:lower(), prefix:lower())
+  end
+  return vim.startswith(value, prefix)
+end
+
 --- Turns the result of a `textDocument/completion` request into vim-compatible
 --- |complete-items|.
 ---
@@ -245,8 +258,16 @@ function M._lsp_to_complete_items(result, prefix, client_id)
   else
     ---@param item lsp.CompletionItem
     matches = function(item)
-      local text = item.filterText or item.label
-      return next(vim.fn.matchfuzzy({ text }, prefix)) ~= nil
+      if item.filterText then
+        return match_item_by_value(item.filterText, prefix)
+      end
+
+      if item.textEdit then
+        -- server took care of filtering
+        return true
+      end
+
+      return match_item_by_value(item.label, prefix)
     end
   end
 
@@ -272,7 +293,7 @@ function M._lsp_to_complete_items(result, prefix, client_id)
         icase = 1,
         dup = 1,
         empty = 1,
-        hl_group = hl_group,
+        abbr_hlgroup = hl_group,
         user_data = {
           nvim = {
             lsp = {
@@ -316,7 +337,7 @@ local function adjust_start_col(lnum, line, items, encoding)
     end
   end
   if min_start_char then
-    return lsp.util._str_byteindex_enc(line, min_start_char, encoding)
+    return vim.str_byteindex(line, encoding, min_start_char, false)
   else
     return nil
   end
@@ -539,35 +560,24 @@ local function on_complete_done()
 
     -- Remove the already inserted word.
     local start_char = cursor_col - #completed_item.word
-    local line = api.nvim_buf_get_lines(bufnr, cursor_row, cursor_row + 1, true)[1]
-    api.nvim_buf_set_text(bufnr, cursor_row, start_char, cursor_row, #line, { '' })
-    return line:sub(cursor_col + 1)
+    api.nvim_buf_set_text(bufnr, cursor_row, start_char, cursor_row, cursor_col, { '' })
   end
 
-  --- @param suffix? string
-  local function apply_snippet_and_command(suffix)
+  local function apply_snippet_and_command()
     if expand_snippet then
-      apply_snippet(completion_item, suffix)
+      apply_snippet(completion_item)
     end
 
     local command = completion_item.command
     if command then
-      client:_exec_cmd(command, { bufnr = bufnr }, nil, function()
-        vim.lsp.log.warn(
-          string.format(
-            'Language server `%s` does not support command `%s`. This command may require a client extension.',
-            client.name,
-            command.command
-          )
-        )
-      end)
+      client:exec_cmd(command, { bufnr = bufnr })
     end
   end
 
   if completion_item.additionalTextEdits and next(completion_item.additionalTextEdits) then
-    local suffix = clear_word()
+    clear_word()
     lsp.util.apply_text_edits(completion_item.additionalTextEdits, bufnr, offset_encoding)
-    apply_snippet_and_command(suffix)
+    apply_snippet_and_command()
   elseif resolve_provider and type(completion_item) == 'table' then
     local changedtick = vim.b[bufnr].changedtick
 
@@ -577,7 +587,7 @@ local function on_complete_done()
         return
       end
 
-      local suffix = clear_word()
+      clear_word()
       if err then
         vim.notify_once(err.message, vim.log.levels.WARN)
       elseif result and result.additionalTextEdits then
@@ -587,16 +597,16 @@ local function on_complete_done()
         end
       end
 
-      apply_snippet_and_command(suffix)
+      apply_snippet_and_command()
     end, bufnr)
   else
-    local suffix = clear_word()
-    apply_snippet_and_command(suffix)
+    clear_word()
+    apply_snippet_and_command()
   end
 end
 
 --- @class vim.lsp.completion.BufferOpts
---- @field autotrigger? boolean Whether to trigger completion automatically. Default: false
+--- @field autotrigger? boolean  Default: false When true, completion triggers automatically based on the server's `triggerCharacters`.
 --- @field convert? fun(item: lsp.CompletionItem): table Transforms an LSP CompletionItem to |complete-items|.
 
 ---@param client_id integer