revert: "fix(lsp): use buffer scheme for files not stored on disk" (#22604)

Although using `buffer://` for unsaved file buffers fixes issues with
language servers like eclipse.jdt.ls or ansible-language-server, it
breaks completion and signature help for clangd.

A regression is worse than a fix for something else, so this reverts
commit 896d672736.

The spec change is also still in dicussion, see
https://github.com/microsoft/language-server-protocol/pull/1679#discussion_r1130704886

runtime/lua/vim/lsp.lua

@@ -369,7 +369,7 @@ do
   --- @field offset_encoding "utf-8"|"utf-16"|"utf-32"
   ---
   --- @class CTBufferState
-  --- @field uri string uri of the buffer
+  --- @field name string name of the buffer
   --- @field lines string[] snapshot of buffer lines from last didChange
   --- @field lines_tmp string[]
   --- @field pending_changes table[] List of debounced changes in incremental sync mode
@@ -488,12 +488,8 @@ do
     if buf_state then
       buf_state.refs = buf_state.refs + 1
     else
-      local uri = vim.uri_from_bufnr(bufnr)
-      if not uv.fs_stat(api.nvim_buf_get_name(bufnr)) then
-        uri = uri:gsub('^file://', 'buffer://')
-      end
       buf_state = {
-        uri = uri,
+        name = api.nvim_buf_get_name(bufnr),
         lines = {},
         lines_tmp = {},
         pending_changes = {},
@@ -508,26 +504,12 @@ do
   end
 
   ---@private
-  ---@param client table
-  ---@param bufnr integer
-  ---@return string uri
-  function changetracking._get_uri(client, bufnr)
+  function changetracking._get_and_set_name(client, bufnr, name)
     local state = state_by_group[get_group(client)] or {}
     local buf_state = (state.buffers or {})[bufnr]
-    return assert(buf_state.uri, 'Must have an URI set')
-  end
-
-  ---@private
-  ---@param client table
-  ---@param bufnr integer
-  ---@param uri string
-  ---@return string uri
-  function changetracking._get_and_set_uri(client, bufnr, uri)
-    local state = state_by_group[get_group(client)] or {}
-    local buf_state = (state.buffers or {})[bufnr]
-    local old_uri = buf_state.uri
-    buf_state.uri = uri
-    return old_uri
+    local old_name = buf_state.name
+    buf_state.name = name
+    return old_name
   end
 
   ---@private
@@ -614,7 +596,7 @@ do
         { text = buf_get_full_text(bufnr) },
       }
     end
-    local uri = buf_state.uri
+    local uri = vim.uri_from_bufnr(bufnr)
     for _, client in pairs(state.clients) do
       if not client.is_stopped() and lsp.buf_is_attached(bufnr, client.id) then
         client.notify('textDocument/didChange', {
@@ -727,14 +709,11 @@ local function text_document_did_open_handler(bufnr, client)
     return
   end
   local filetype = nvim_buf_get_option(bufnr, 'filetype')
-  local uri = vim.uri_from_bufnr(bufnr)
-  if not uv.fs_stat(api.nvim_buf_get_name(bufnr)) then
-    uri = uri:gsub('^file://', 'buffer://')
-  end
+
   local params = {
     textDocument = {
       version = 0,
-      uri = uri,
+      uri = vim.uri_from_bufnr(bufnr),
       languageId = client.config.get_language_id(bufnr, filetype),
       text = buf_get_full_text(bufnr),
     },
@@ -1611,13 +1590,8 @@ local function text_document_did_save_handler(bufnr)
   local text = once(buf_get_full_text)
   for_each_buffer_client(bufnr, function(client)
     local name = api.nvim_buf_get_name(bufnr)
-    local old_uri = changetracking._get_and_set_uri(client, bufnr, uri)
-    if old_uri and name ~= old_uri then
-      client.notify('textDocument/didClose', {
-        textDocument = {
-          uri = old_uri,
-        },
-      })
+    local old_name = changetracking._get_and_set_name(client, bufnr, name)
+    if old_name and name ~= old_name then
       client.notify('textDocument/didOpen', {
         textDocument = {
           version = 0,
@@ -1720,12 +1694,8 @@ function lsp.buf_attach_client(bufnr, client_id)
         end)
       end,
       on_detach = function()
+        local params = { textDocument = { uri = uri } }
         for_each_buffer_client(bufnr, function(client, _)
-          local params = {
-            textDocument = {
-              uri = changetracking._get_uri(client, bufnr),
-            },
-          }
           changetracking.reset_buf(client, bufnr)
           if vim.tbl_get(client.server_capabilities, 'textDocumentSync', 'openClose') then
             client.notify('textDocument/didClose', params)

runtime/lua/vim/lsp/util.lua

@@ -2032,12 +2032,7 @@ end
 ---@returns `TextDocumentIdentifier`
 ---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocumentIdentifier
 function M.make_text_document_params(bufnr)
-  bufnr = bufnr or 0
-  local uri = vim.uri_from_bufnr(bufnr)
-  if not uv.fs_stat(api.nvim_buf_get_name(bufnr)) then
-    uri = uri:gsub('^file://', 'buffer://')
-  end
-  return { uri = uri }
+  return { uri = vim.uri_from_bufnr(bufnr or 0) }
 end
 
 --- Create the workspace params
@@ -2070,7 +2065,7 @@ function M.make_formatting_params(options)
     insertSpaces = vim.bo.expandtab,
   })
   return {
-    textDocument = M.make_text_document_params(0),
+    textDocument = { uri = vim.uri_from_bufnr(0) },
     options = options,
   }
 end

test/functional/fixtures/fake-lsp-server.lua

@@ -272,7 +272,6 @@ function tests.text_document_save_did_open()
     end;
     body = function()
       notify('start')
-      expect_notification('textDocument/didClose')
       expect_notification('textDocument/didOpen')
       expect_notification('textDocument/didSave')
       notify('shutdown')
@@ -293,8 +292,6 @@ function tests.text_document_sync_save_bool()
     end;
     body = function()
       notify('start')
-      expect_notification('textDocument/didClose')
-      expect_notification('textDocument/didOpen')
       expect_notification('textDocument/didSave', {textDocument = { uri = "file://" }})
       notify('shutdown')
     end;
@@ -316,8 +313,6 @@ function tests.text_document_sync_save_includeText()
     end;
     body = function()
       notify('start')
-      expect_notification('textDocument/didClose')
-      expect_notification('textDocument/didOpen')
       expect_notification('textDocument/didSave', {
         textDocument = {
           uri = "file://"
@@ -464,7 +459,7 @@ function tests.basic_check_buffer_open()
         textDocument = {
           languageId = "";
           text = table.concat({"testing"; "123"}, "\n") .. '\n';
-          uri = "buffer://";
+          uri = "file://";
           version = 0;
         };
       })
@@ -491,13 +486,13 @@ function tests.basic_check_buffer_open_and_change()
         textDocument = {
           languageId = "";
           text = table.concat({"testing"; "123"}, "\n") .. '\n';
-          uri = "buffer://";
+          uri = "file://";
           version = 0;
         };
       })
       expect_notification('textDocument/didChange', {
         textDocument = {
-          uri = "buffer://";
+          uri = "file://";
           version = 3;
         };
         contentChanges = {
@@ -527,13 +522,13 @@ function tests.basic_check_buffer_open_and_change_noeol()
         textDocument = {
           languageId = "";
           text = table.concat({"testing"; "123"}, "\n");
-          uri = "buffer://";
+          uri = "file://";
           version = 0;
         };
       })
       expect_notification('textDocument/didChange', {
         textDocument = {
-          uri = "buffer://";
+          uri = "file://";
           version = 3;
         };
         contentChanges = {
@@ -562,13 +557,13 @@ function tests.basic_check_buffer_open_and_change_multi()
         textDocument = {
           languageId = "";
           text = table.concat({"testing"; "123"}, "\n") .. '\n';
-          uri = "buffer://";
+          uri = "file://";
           version = 0;
         };
       })
       expect_notification('textDocument/didChange', {
         textDocument = {
-          uri = "buffer://";
+          uri = "file://";
           version = 3;
         };
         contentChanges = {
@@ -577,7 +572,7 @@ function tests.basic_check_buffer_open_and_change_multi()
       })
       expect_notification('textDocument/didChange', {
         textDocument = {
-          uri = "buffer://";
+          uri = "file://";
           version = 4;
         };
         contentChanges = {
@@ -607,13 +602,13 @@ function tests.basic_check_buffer_open_and_change_multi_and_close()
         textDocument = {
           languageId = "";
           text = table.concat({"testing"; "123"}, "\n") .. '\n';
-          uri = "buffer://";
+          uri = "file://";
           version = 0;
         };
       })
       expect_notification('textDocument/didChange', {
         textDocument = {
-          uri = "buffer://";
+          uri = "file://";
           version = 3;
         };
         contentChanges = {
@@ -622,7 +617,7 @@ function tests.basic_check_buffer_open_and_change_multi_and_close()
       })
       expect_notification('textDocument/didChange', {
         textDocument = {
-          uri = "buffer://";
+          uri = "file://";
           version = 4;
         };
         contentChanges = {
@@ -631,7 +626,7 @@ function tests.basic_check_buffer_open_and_change_multi_and_close()
       })
       expect_notification('textDocument/didClose', {
         textDocument = {
-          uri = "buffer://";
+          uri = "file://";
         };
       })
       expect_notification("finish")
@@ -665,13 +660,13 @@ function tests.basic_check_buffer_open_and_change_incremental()
         textDocument = {
           languageId = "";
           text = table.concat({"testing"; "123"}, "\n") .. '\n';
-          uri = "buffer://";
+          uri = "file://";
           version = 0;
         };
       })
       expect_notification('textDocument/didChange', {
         textDocument = {
-          uri = "buffer://";
+          uri = "file://";
           version = 3;
         };
         contentChanges = {
@@ -708,13 +703,13 @@ function tests.basic_check_buffer_open_and_change_incremental_editing()
         textDocument = {
           languageId = "";
           text = table.concat({"testing"; "123"}, "\n");
-          uri = "buffer://";
+          uri = "file://";
           version = 0;
         };
       })
       expect_notification('textDocument/didChange', {
         textDocument = {
-          uri = "buffer://";
+          uri = "file://";
           version = 3;
         };
         contentChanges = {