Add wrappers around boost::filesystem methods that handle the

required mangling of long filenames on Windows.

Also wrap lots of missing places (e.g. calls to asdcplib, libxml++,
libcxml etc.) in dcp::filesystem::fix_long_path().

The idea is to keep paths un-mangled until they we call some
filesystem-related API and mangle them at that point.  Otherwise
we end up serialising mangled names, which seems like it will
not end well.

Should fix DoM #2623.

4 files changed, 87 insertions, 12 deletions

diff --git a/test/encryption_test.cc b/test/encryption_test.cc
index f2a40843..358a3fd9 100644
--- a/test/encryption_test.cc
+++ b/test/encryption_test.cc
@@ -36,6 +36,7 @@
 #include "dcp.h"
 #include "certificate_chain.h"
 #include "cpl.h"
+#include "filesystem.h"
 #include "mono_picture_asset.h"
 #include "picture_asset_writer.h"
 #include "sound_asset_writer.h"
@@ -155,6 +156,11 @@ BOOST_AUTO_TEST_CASE (encryption_test)
 
 	kdm.encrypt (signer, signer->leaf(), vector<string>(), dcp::Formulation::MODIFIED_TRANSITIONAL_1, true, 0).as_xml("build/test/encryption_test.kdm.xml");
 
+	/* Make sure we aren't in a UNC current working directory otherwise the use of cmd.exe
+	 * in system() below will fail.
+	 */
+	boost::filesystem::current_path(dcp::filesystem::unfix_long_path(boost::filesystem::current_path()));
+
 	int r = system (
 		"xmllint --path schema --nonet --noout --schema schema/SMPTE-430-1-2006-Amd-1-2009-KDM.xsd build/test/encryption_test.kdm.xml "
 #ifndef LIBDCP_WINDOWS
diff --git a/test/file_test.cc b/test/filesystem_test.cc
index 8c6ded29..fc13db99 100644
--- a/test/file_test.cc
+++ b/test/filesystem_test.cc
@@ -33,6 +33,7 @@
 
 
 #include "file.h"
+#include "filesystem.h"
 #include <boost/filesystem.hpp>
 #include <boost/test/unit_test.hpp>
 
@@ -40,16 +41,23 @@
 BOOST_AUTO_TEST_CASE (fix_long_path_test)
 {
 #ifdef LIBDCP_WINDOWS
-	BOOST_CHECK_EQUAL (dcp::fix_long_path("c:\\foo"), "\\\\?\\c:\\foo");
-	BOOST_CHECK_EQUAL (dcp::fix_long_path("c:\\foo\\bar"), "\\\\?\\c:\\foo\\bar");
-	boost::filesystem::path fixed_bar = "\\\\?\\";
-	fixed_bar += boost::filesystem::current_path();
-	fixed_bar /= "bar";
-	BOOST_CHECK_EQUAL (dcp::fix_long_path("bar"), fixed_bar);
-
-	BOOST_CHECK_EQUAL (dcp::fix_long_path("\\\\?\\c:\\foo"), "\\\\?\\c:\\foo");
+	BOOST_CHECK_EQUAL(dcp::filesystem::fix_long_path("c:\\foo"), "\\\\?\\c:\\foo");
+	BOOST_CHECK_EQUAL(dcp::filesystem::fix_long_path("c:\\foo\\bar"), "\\\\?\\c:\\foo\\bar");
+	BOOST_CHECK_EQUAL(dcp::filesystem::fix_long_path("\\\\?\\c:\\foo"), "\\\\?\\c:\\foo");
 #else
-	BOOST_CHECK_EQUAL (dcp::fix_long_path("foo/bar/baz"), "foo/bar/baz");
+	BOOST_CHECK_EQUAL(dcp::filesystem::fix_long_path("foo/bar/baz"), "foo/bar/baz");
+#endif
+}
+
+
+BOOST_AUTO_TEST_CASE(unfix_long_path_test)
+{
+#ifdef LIBDCP_WINDOWS
+	BOOST_CHECK_EQUAL(dcp::filesystem::unfix_long_path("c:\\foo"), "c:\\foo");
+	BOOST_CHECK_EQUAL(dcp::filesystem::unfix_long_path("\\\\?\\c:\\foo"), "c:\\foo");
+#else
+	BOOST_CHECK_EQUAL(dcp::filesystem::unfix_long_path("c:\\foo"), "c:\\foo");
+	BOOST_CHECK_EQUAL(dcp::filesystem::unfix_long_path("\\\\?\\c:\\foo"), "\\\\?\\c:\\foo");
 #endif
 }
 
@@ -59,14 +67,15 @@ BOOST_AUTO_TEST_CASE (windows_long_filename_test)
 {
 	using namespace boost::filesystem;
 
-	path too_long = current_path() / "build\\test\\a\\really\\very\\long\\filesystem\\path\\indeed\\that\\will\\be\\so\\long\\that\\windows\\cannot\\normally\\cope\\with\\it\\unless\\we\\add\\this\\crazy\\prefix\\and\\then\\magically\\it\\can\\do\\it\\fine\\I\\dont\\really\\know\\why\\its\\like\\that\\but\\hey\\it\\is\\so\\here\\we\\are\\what\\can\\we\\do\\other\\than\\bodge\\it";
+	/* Make sure current_path() is not already fixed by using our dcp::filesystem version */
+	path too_long = dcp::filesystem::current_path() / "build\\test\\a\\really\\very\\long\\filesystem\\path\\indeed\\that\\will\\be\\so\\long\\that\\windows\\cannot\\normally\\cope\\with\\it\\unless\\we\\add\\this\\crazy\\prefix\\and\\then\\magically\\it\\can\\do\\it\\fine\\I\\dont\\really\\know\\why\\its\\like\\that\\but\\hey\\it\\is\\so\\here\\we\\are\\what\\can\\we\\do\\other\\than\\bodge\\it";
 
 	BOOST_CHECK (too_long.string().length() > 260);
 	boost::system::error_code ec;
 	create_directories (too_long, ec);
 	BOOST_CHECK (ec);
 
-	path fixed_path = dcp::fix_long_path(too_long);
+	path fixed_path = dcp::filesystem::fix_long_path(too_long);
 	create_directories (fixed_path, ec);
 	BOOST_CHECK (!ec);
 
diff --git a/test/long_filenames_test.cc b/test/long_filenames_test.cc
new file mode 100644
index 00000000..f8189884
--- /dev/null
+++ b/test/long_filenames_test.cc
@@ -0,0 +1,59 @@
+/*
+    Copyright (C) 2023 Carl Hetherington <cth@carlh.net>
+
+    This file is part of libdcp.
+
+    libdcp is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    libdcp is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with libdcp.  If not, see <http://www.gnu.org/licenses/>.
+
+    In addition, as a special exception, the copyright holders give
+    permission to link the code of portions of this program with the
+    OpenSSL library under certain conditions as described in each
+    individual source file, and distribute linked combinations
+    including the two.
+
+    You must obey the GNU General Public License in all respects
+    for all of the code used other than OpenSSL.  If you modify
+    file(s) with this exception, you may extend this exception to your
+    version of the file(s), but you are not obligated to do so.  If you
+    do not wish to do so, delete this exception statement from your
+    version.  If you delete this exception statement from all source
+    files in the program, then also delete it here.
+*/
+
+
+#include "dcp.h"
+#include "filesystem.h"
+#include <boost/filesystem.hpp>
+#include <boost/test/unit_test.hpp>
+
+
+BOOST_AUTO_TEST_CASE(load_dcp_with_long_filename)
+{
+	boost::filesystem::path long_name = "build/test";
+	for (int i = 0; i < 27; ++i) {
+		long_name /= "letsmakeitlong";
+	}
+
+	dcp::filesystem::remove_all(long_name);
+	dcp::filesystem::create_directories(long_name);
+	for (auto file: dcp::filesystem::directory_iterator("test/ref/DCP/dcp_test1")) {
+		dcp::filesystem::copy(file.path(), long_name / file.path().filename());
+	}
+
+	dcp::DCP dcp(long_name);
+	BOOST_CHECK_NO_THROW(dcp.read());
+}
+
+
+
diff --git a/test/wscript b/test/wscript
index bc786322..4d9278eb 100644
--- a/test/wscript
+++ b/test/wscript
@@ -82,7 +82,7 @@ def build(bld):
                  effect_test.cc
                  encryption_test.cc
                  exception_test.cc
-                 file_test.cc
+                 filesystem_test.cc
                  fraction_test.cc
                  frame_info_hash_test.cc
                  gamma_transfer_function_test.cc
@@ -90,6 +90,7 @@ def build(bld):
                  interop_load_font_test.cc
                  interop_subtitle_test.cc
                  local_time_test.cc
+                 long_filenames_test.cc
                  make_digest_test.cc
                  markers_test.cc
                  mca_test.cc