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.

1 files changed, 2 insertions, 44 deletions

diff --git a/src/file.cc b/src/file.cc
index b5d2eed4..36102f72 100644
--- a/src/file.cc
+++ b/src/file.cc
@@ -34,7 +34,7 @@
 
 #include "dcp_assert.h"
 #include "file.h"
-#include <boost/algorithm/string.hpp>
+#include "filesystem.h"
 #ifdef LIBDCP_WINDOWS
 #include <errhandlingapi.h>
 #endif
@@ -57,7 +57,7 @@ File::File(boost::filesystem::path path, std::string mode)
 	SetLastError(0);
 	std::wstring mode_wide(mode.begin(), mode.end());
 	/* c_str() here should give a UTF-16 string */
-	_file = _wfopen(fix_long_path(path).c_str(), mode_wide.c_str());
+	_file = _wfopen(dcp::filesystem::fix_long_path(path).c_str(), mode_wide.c_str());
 	if (!_file) {
 		_open_error = GetLastError();
 	}
@@ -216,45 +216,3 @@ File::error ()
 	DCP_ASSERT(_file);
 	return ferror(_file);
 }
-
-
-/** Windows can't "by default" cope with paths longer than 260 characters, so if you pass such a path to
- *  any boost::filesystem method it will fail.  There is a "fix" for this, which is to prepend
- *  the string \\?\ to the path.  This will make it work, so long as:
- *  - the path is absolute.
- *  - the path only uses backslashes.
- *  - individual path components are "short enough" (probably less than 255 characters)
- *
- *  See https://www.boost.org/doc/libs/1_57_0/libs/filesystem/doc/reference.html under
- *  "Warning: Long paths on Windows" for some details.
- *
- *  Our fopen_boost uses this method to get this fix, but any other calls to boost::filesystem
- *  will not unless this method is explicitly called to pre-process the pathname.
- */
-boost::filesystem::path
-dcp::fix_long_path (boost::filesystem::path long_path)
-{
-#ifdef LIBDCP_WINDOWS
-	using namespace boost::filesystem;
-
-	if (boost::algorithm::starts_with(long_path.string(), "\\\\")) {
-		/* This could mean it starts with \\ (i.e. a SMB path) or \\?\ (a long path)
-		 * or a variety of other things... anyway, we'll leave it alone.
-		 */
-		return long_path;
-	}
-
-	/* We have to make the path canonical but we can't call canonical() on the long path
-	 * as it will fail.  So we'll sort of do it ourselves (possibly badly).
-	 */
-	path fixed = "\\\\?\\";
-	if (long_path.is_absolute()) {
-		fixed += long_path.make_preferred();
-	} else {
-		fixed += boost::filesystem::current_path() / long_path.make_preferred();
-	}
-	return fixed;
-#else
-	return long_path;
-#endif
-}