Fix 11 Gitea issues (#29, #30, #31, #35, #38, #41, #42, #43, #44, #45, #46)

#29 - compression_level now used in data_compress()
#30 - chunk_size no longer truncated to 32-bit
#31 - chmod/chown failures now logged
#35 - strtok -> strtok_r for thread safety
#38 - open_next_directory returns -1 on opendir failure
#41 - file_send_sendfile uses compression_level param
#42 - dirname() uses copy to avoid modifying input
#43 - delete_extras_walk checks manifest before rmdir
#44 - server_host/port moved into Config struct
#45 - SSH parse_remote_dest uses dynamic allocation
#46 - send_chunk refactored, reduced nesting/duplication

src/shared/compression.c

@@ -7,7 +7,6 @@
 #define INITIAL_DECOMPRESS_BUF_SIZE (1024 * 1024)
 
 Data* data_compress(Data* data_to_compress, int compression_level) {
-  (void)compression_level;
   log_message(LOG_LEVEL_DEBUG, "Starting to compress data");
   size_t dst_size = ZSTD_compressBound(data_to_compress->size);
   Data* compressed_data = data_create_empty(dst_size);
@@ -21,6 +20,14 @@ Data* data_compress(Data* data_to_compress, int compression_level) {
     return NULL;
   }
 
+  size_t zret = ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, compression_level);
+  if (ZSTD_isError(zret)) {
+    log_message(LOG_LEVEL_ERROR, "Failed to set compression level: %s", ZSTD_getErrorName(zret));
+    ZSTD_freeCCtx(cctx);
+    data_destroy(compressed_data);
+    return NULL;
+  }
+
   ZSTD_inBuffer input = {data_to_compress->data, data_to_compress->size, 0};
   ZSTD_outBuffer output = {compressed_data->data, dst_size, 0};