[fix](fe) Infer compression before skipping empty schema files

fe/fe-core/src/main/java/org/apache/doris/tablefunction/ExternalFileTableValuedFunction.java

@@ -560,7 +560,9 @@ private boolean isFileContentEmpty(TBrokerFileStatus fileStatus) {
         if (Util.isCsvFormat(fileFormatProperties.getFileFormatType())
                 || fileFormatProperties.getFileFormatType() == TFileFormatType.FORMAT_JSON) {
             int magicNumberBytes = 0;
-            switch (fileFormatProperties.getCompressionType()) {
+            TFileCompressType compressType = Util.getOrInferCompressType(
+                    fileFormatProperties.getCompressionType(), fileStatus.getPath());
+            switch (compressType) {
                 case GZ:
                     magicNumberBytes = 20;
                     break;

regression-test/data/external_table_p0/tvf/test_empty_first_compressed_schema.out

@@ -0,0 +1,9 @@
+-- This file is automatically generated. You should know what you did if you want to edit this
+-- !csv_empty_first_gzip --
+1	alpha	1.10
+2	beta	2.20
+
+-- !json_empty_first_gzip --
+1	beijing	1.1
+2	shanghai	2.2
+

regression-test/suites/external_table_p0/tvf/test_empty_first_compressed_schema.groovy

@@ -0,0 +1,47 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+suite("test_empty_first_compressed_schema", "p0,external") {
+    String ak = getS3AK()
+    String sk = getS3SK()
+    String s3Endpoint = getS3Endpoint()
+    String bucket = context.config.otherConfigs.get("s3BucketName")
+    String baseUri = "https://${bucket}.${s3Endpoint}/regression/tvf/test_empty_first_compressed_schema"
+
+    order_qt_csv_empty_first_gzip """
+        select id, name, metric from
+        s3(
+            "URI" = "${baseUri}/csv/*.csv.gz",
+            "s3.access_key" = "${ak}",
+            "s3.secret_key" = "${sk}",
+            "FORMAT" = "csv_with_names",
+            "column_separator" = ",",
+            "use_path_style" = "false") order by id;
+    """
+
+    order_qt_json_empty_first_gzip """
+        select id, city, metric from
+        s3(
+            "URI" = "${baseUri}/json/*.jsonl.gz",
+            "s3.access_key" = "${ak}",
+            "s3.secret_key" = "${sk}",
+            "FORMAT" = "json",
+            "read_json_by_line" = "true",
+            "fuzzy_parse" = "true",
+            "use_path_style" = "false") order by id;
+    """
+}