In unarchiveToDirectory(), make zero-byte files in the archive delete existing files instead of overwrite them.

include/system.hpp

@@ -146,6 +146,9 @@ or
 
 	tar -xf archivePath --zstd -C dirPath
 
+As a special case, zero-byte files in the archive cause the unarchiver to delete existing files instead of overwriting them.
+This is useful for removing presets in .vcvplugin packages, for example.
+
 Throws on error.
 */
 void unarchiveToDirectory(const std::string& archivePath, const std::string& dirPath);

src/system.cpp

@@ -575,6 +575,12 @@ static void unarchiveToDirectory(const std::string& archivePath, const std::vect
 		archive_entry_set_pathname(entry, entryPath.c_str());
 #endif
 
+		// Delete zero-byte files
+		if (archive_entry_filetype(entry) == AE_IFREG && archive_entry_size(entry) == 0) {
+			remove(entryPath);
+			continue;
+		}
+
 		// Write entry to disk
 		r = archive_write_header(disk, entry);
 		if (r < ARCHIVE_OK)