Merge pull request #1639 from DeusData/fix/yaml-interior-anchor-chars

fix(yaml): treat interior `*` and `&` as text, not as alias/anchor indicators

src/cli/config_yaml_edit.c

@@ -1254,23 +1254,54 @@ static int yaml_find_comment(const char *data, size_t start, size_t end, size_t
     return 0;
 }
 
+/* `&` and `*` are anchor/alias indicators only where a NODE begins. Once a
+ * plain scalar has started, they are ordinary characters.
+ *
+ * This used to reject them anywhere in the range, so a value containing prose
+ * asterisks — `use *emphasis* here`, a kaomoji, a glob in a description — was
+ * refused as if it were an alias. Reported against a real 16 KB Hermes config
+ * where this was one of four constructs that made the file permanently
+ * un-editable by us (#1631, root-caused by @rg6304 with an isolated repro).
+ *
+ * The test is positional and deliberately conservative: an indicator is only
+ * honoured as one when nothing has appeared before it in the value. `key: *a`
+ * is still an alias and still refused; `key: 2 * 3` and `key: a*b` are text.
+ * `{`/`}` keep their existing treatment — empty flow mappings are a separate
+ * change with its own semantics. */
 static int yaml_range_has_unsupported(const char *data, size_t start, size_t end) {
     char quote = '\0';
+    /* Last significant character seen, so an indicator can be judged by what
+     * PRECEDES it. The scanned range covers a whole line including its key, so
+     * "first character in the range" is not the same as "start of a node" —
+     * in `command: &shared` the `&` is an anchor even though `command:` came
+     * first. A node begins at the range start, after a mapping colon, or after
+     * a block-sequence dash. */
+    char previous = '\0';
     for (size_t i = start; i < end; i++) {
         bool is_plain = false;
         if (yaml_scan_quote(data, end, &i, &quote, &is_plain) != 0) {
             return YAML_MATCH;
         }
         if (!is_plain) {
+            previous = 'q';
             continue;
         }
         char c = data[i];
         if (c == '#' && (i == start || data[i - YAML_UNIT] == ' ')) {
             break;
         }
-        if (c == '{' || c == '}' || c == '&' || c == '*') {
+        if (c == '{' || c == '}') {
             return YAML_MATCH;
         }
+        if (c == '&' || c == '*') {
+            bool begins_node = previous == '\0' || previous == ':' || previous == '-';
+            if (begins_node) {
+                return YAML_MATCH;
+            }
+        }
+        if (c != ' ' && c != '\t') {
+            previous = c;
+        }
         if (c == '<' && i + YAML_ENTRY_INDENT < end && data[i + YAML_UNIT] == '<' &&
             data[i + YAML_ENTRY_INDENT] == ':') {
             return YAML_MATCH;

tests/test_config_yaml_edit.c

@@ -1501,6 +1501,44 @@ TEST(config_yaml_edit_nested_sequence_ambiguity_fails_byte_identically) {
 }
 
 #ifndef _WIN32
+/* #1631: an interior `*` in a written value is ordinary text, not an alias.
+ * A real 16 KB Hermes config was permanently un-editable because prose
+ * asterisks in a personality string were read as aliases (root-caused by
+ * @rg6304 with an isolated repro).
+ *
+ * The asterisk is in the ENTRY BLOCK deliberately: that is the range the
+ * editor validates. An earlier version of this test put it in an untouched
+ * foreign section, which is never scanned - so it passed with the fix
+ * reverted and proved nothing. */
+TEST(config_yaml_edit_accepts_interior_asterisk_in_plain_scalar_issue1631) {
+    const char *original = "existing:\n  keep: 1\n";
+    yaml_fixture_t fixture;
+    ASSERT_EQ(yaml_fixture_init(&fixture, original), 0);
+    ASSERT_EQ(cbm_yaml_upsert_mapping_entry(fixture.path, "hooks", "cbm",
+                                            "    value: use *emphasis* and 2 * 3\n"),
+              0);
+    char *after = yaml_read_alloc(fixture.path);
+    ASSERT_NOT_NULL(after);
+    ASSERT_NOT_NULL(strstr(after, "value: use *emphasis* and 2 * 3"));
+    free(after);
+    ASSERT_EQ(cbm_unlink(fixture.path), 0);
+    th_cleanup(fixture.dir);
+    PASS();
+}
+TEST(config_yaml_edit_still_refuses_leading_alias_issue1631) {
+    const char *original = "existing:\n  keep: 1\n";
+    yaml_fixture_t fixture;
+    ASSERT_EQ(yaml_fixture_init(&fixture, original), 0);
+    ASSERT(cbm_yaml_upsert_mapping_entry(fixture.path, "hooks", "cbm", "    value: *alias\n") != 0);
+    char *after = yaml_read_alloc(fixture.path);
+    ASSERT_NOT_NULL(after);
+    ASSERT_STR_EQ(after, original);
+    free(after);
+    ASSERT_EQ(cbm_unlink(fixture.path), 0);
+    th_cleanup(fixture.dir);
+    PASS();
+}
+
 TEST(config_yaml_edit_nested_sequence_rejects_symlink_byte_identically) {
     const char *original = "hooks:\n  pre_llm_call:\n    - id: \"other\"\n";
     yaml_fixture_t fixture;
@@ -1573,6 +1611,8 @@ SUITE(config_yaml_edit) {
     RUN_TEST(config_yaml_edit_nested_sequence_removes_only_exact_canonical_item);
     RUN_TEST(config_yaml_edit_nested_sequence_ambiguity_fails_byte_identically);
 #ifndef _WIN32
+    RUN_TEST(config_yaml_edit_accepts_interior_asterisk_in_plain_scalar_issue1631);
+    RUN_TEST(config_yaml_edit_still_refuses_leading_alias_issue1631);
     RUN_TEST(config_yaml_edit_nested_sequence_rejects_symlink_byte_identically);
 #endif
 }