fix(lsp): fix lookup of boolean values in workspace/configuration (#18026)

4 files changed, 9 insertions, 4 deletions

diff --git a/runtime/lua/vim/lsp/handlers.lua b/runtime/lua/vim/lsp/handlers.lua
index f5aefd4402..9871f00677 100644
--- a/runtime/lua/vim/lsp/handlers.lua
+++ b/runtime/lua/vim/lsp/handlers.lua
@@ -141,7 +141,7 @@ M['workspace/configuration'] = function(_, result, ctx)
   local response = {}
   for _, item in ipairs(result.items) do
     if item.section then
-      local value = util.lookup_section(client.config.settings, item.section) or vim.NIL
+      local value = util.lookup_section(client.config.settings, item.section)
       -- For empty sections with no explicit '' key, return settings as is
       if value == vim.NIL and item.section == '' then
         value = client.config.settings or vim.NIL
diff --git a/runtime/lua/vim/lsp/util.lua b/runtime/lua/vim/lsp/util.lua
index 401dac9acd..30587afb38 100644
--- a/runtime/lua/vim/lsp/util.lua
+++ b/runtime/lua/vim/lsp/util.lua
@@ -1950,8 +1950,8 @@ end
 function M.lookup_section(settings, section)
   for part in vim.gsplit(section, '.', true) do
     settings = settings[part]
-    if not settings then
-      return
+    if settings == nil then
+      return vim.NIL
     end
   end
   return settings
diff --git a/test/functional/fixtures/fake-lsp-server.lua b/test/functional/fixtures/fake-lsp-server.lua
index 5c0de50731..7ff3713d41 100644
--- a/test/functional/fixtures/fake-lsp-server.lua
+++ b/test/functional/fixtures/fake-lsp-server.lua
@@ -119,8 +119,10 @@ function tests.check_workspace_configuration()
       notify('workspace/configuration', { items = {
               { section = "testSetting1" };
               { section = "testSetting2" };
+              { section = "test.Setting3" };
+              { section = "test.Setting4" };
           } })
-      expect_notification('workspace/configuration', { true; vim.NIL})
+      expect_notification('workspace/configuration', { true; false; 'nested'; vim.NIL})
       notify('shutdown')
     end;
   }
diff --git a/test/functional/plugin/lsp_spec.lua b/test/functional/plugin/lsp_spec.lua
index 6cda9af0f4..436b431e38 100644
--- a/test/functional/plugin/lsp_spec.lua
+++ b/test/functional/plugin/lsp_spec.lua
@@ -347,6 +347,8 @@ describe('LSP', function()
         {NIL, { items = {
               { section = "testSetting1" };
               { section = "testSetting2" };
+              { section = "test.Setting3" };
+              { section = "test.Setting4" };
           }}, { method="workspace/configuration", client_id=1}};
         {NIL, {}, {method="start", client_id=1}};
       }
@@ -368,6 +370,7 @@ describe('LSP', function()
               client.config.settings = {
                 testSetting1 = true;
                 testSetting2 = false;
+                test = {Setting3 = 'nested' };
             }]=])
           end
           if ctx.method == 'workspace/configuration' then