fix: regenerate feign-hc5 sample with updated ApiResponseDecoder

The feign-hc5 sample was missed during the second commit's regeneration
because setTemplateDir("feign") overrides the filesystem templateDir
from the config, causing the generator to use embedded JAR resources.
After rebuilding the JAR with the updated mustache template, the
feign-hc5 sample now matches feign and feign-no-nullable.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: cziberpv

samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/ApiResponseDecoder.java

@@ -24,6 +24,7 @@
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
 import java.nio.file.Files;
+import java.nio.file.Paths;
 import java.nio.file.StandardCopyOption;
 import java.util.Collection;
 import java.util.Collections;
@@ -36,7 +37,7 @@
 public class ApiResponseDecoder extends JacksonDecoder {
 
     private static final Pattern FILENAME_PATTERN =
-            Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+            Pattern.compile("filename=\"([^\"]+)\"|filename=([^\\s;]+)");
 
     public ApiResponseDecoder(ObjectMapper mapper) {
         super(mapper);
@@ -69,6 +70,9 @@ private boolean isBinaryType(Type type) {
 
     private Object decodeBinary(Response response, Type type) throws IOException {
         Class<?> raw = Types.getRawType(type);
+        if (response.body() == null) {
+            return null;
+        }
         if (byte[].class.isAssignableFrom(raw)) {
             return response.body().asInputStream().readAllBytes();
         }
@@ -82,8 +86,10 @@ private File downloadToTempFile(Response response) throws IOException {
         String filename = extractFilename(response);
         File file;
         if (filename != null) {
+            // Sanitize: strip path components to prevent path traversal
+            String safeName = Paths.get(filename).getFileName().toString();
             java.nio.file.Path tempDir = Files.createTempDirectory("feign-download");
-            file = Files.createFile(tempDir.resolve(filename)).toFile();
+            file = Files.createFile(tempDir.resolve(safeName)).toFile();
             tempDir.toFile().deleteOnExit();
         } else {
             file = Files.createTempFile("download-", "").toFile();
@@ -100,7 +106,10 @@ private String extractFilename(Response response) {
         if (dispositions == null) return null;
         for (String disposition : dispositions) {
             Matcher m = FILENAME_PATTERN.matcher(disposition);
-            if (m.find()) return m.group(1);
+            if (m.find()) {
+                // Group 1: quoted filename (may contain spaces), Group 2: unquoted token
+                return m.group(1) != null ? m.group(1) : m.group(2);
+            }
         }
         return null;
     }