# This patch modifies the json-schema-to-grammar.cpp file to handle 'not: {}' constructs.
#
# Author: https://github.com/simaotwx
# Reference: https://github.com/ggml-org/llama.cpp/issues/14227#issuecomment-3547740835

diff --git a/common/json-schema-to-grammar.cpp b/common/json-schema-to-grammar.cpp
index 478aa1be7..ec0b3b73e 100644
--- a/common/json-schema-to-grammar.cpp
+++ b/common/json-schema-to-grammar.cpp
@@ -822,7 +822,17 @@ public:
             return _add_rule(rule_name, _resolve_ref(schema["$ref"]));
         } else if (schema.contains("oneOf") || schema.contains("anyOf")) {
             std::vector<json> alt_schemas = schema.contains("oneOf") ? schema["oneOf"].get<std::vector<json>>() : schema["anyOf"].get<std::vector<json>>();
-            return _add_rule(rule_name, _generate_union_rule(name, alt_schemas));
+            std::vector<json> filtered_schemas;
+            for (const auto& alt : alt_schemas) {
+                if (alt.is_object() && alt.contains("not")) {
+                    const auto& not_val = alt["not"];
+                    if (not_val.is_object() && not_val.empty()) {
+                        continue;
+                    }
+                }
+                filtered_schemas.push_back(alt);
+            }
+            return _add_rule(rule_name, _generate_union_rule(name, filtered_schemas));
         } else if (schema_type.is_array()) {
             std::vector<json> schema_types;
             for (const auto & t : schema_type) {