cli: make default log revset work without working-copy commit

Spotted while adding an error propagation path from IdPrefixContext.

cli/src/config-schema.json

@@ -389,7 +389,7 @@
                 "log": {
                     "type": "string",
                     "description": "Default set of revisions to show when no explicit revset is given for jj log and similar commands",
-                    "default": "@ | ancestors(immutable_heads().., 2) | trunk()"
+                    "default": "present(@) | ancestors(immutable_heads().., 2) | trunk()"
                 },
                 "short-prefixes": {
                     "type": "string",

cli/src/config/revsets.toml

@@ -3,7 +3,7 @@
 
 [revsets]
 fix = "reachable(@, mutable())"
-log = "@ | ancestors(immutable_heads().., 2) | trunk()"
+log = "present(@) | ancestors(immutable_heads().., 2) | trunk()"
 
 [revset-aliases]
 'trunk()' = '''

cli/tests/test_commit_template.rs

@@ -217,6 +217,19 @@ fn test_log_default() {
     "#);
 }
 
+#[test]
+fn test_log_default_without_working_copy() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_ok(test_env.env_root(), &["git", "init", "repo"]);
+    let repo_path = test_env.env_root().join("repo");
+
+    test_env.jj_cmd_ok(&repo_path, &["workspace", "forget"]);
+    let stdout = test_env.jj_cmd_success(&repo_path, &["log"]);
+    insta::assert_snapshot!(stdout, @r#"
+    ◆  zzzzzzzz root() 00000000
+    "#);
+}
+
 #[test]
 fn test_log_builtin_templates() {
     let test_env = TestEnvironment::default();

docs/config.md

@@ -289,7 +289,8 @@ You can configure the revisions `jj log` would show when neither `-r` nor any pa
 revsets.log = "main@origin.."
 ```
 
-The default value for `revsets.log` is `'@ | ancestors(immutable_heads().., 2) | trunk()'`.
+The default value for `revsets.log` is
+`'present(@) | ancestors(immutable_heads().., 2) | trunk()'`.
 
 ### Graph style