more work on linking file existence and removability

libs/ardour/ardour/file_source.h

@@ -82,6 +82,7 @@ public:
 	
 	static PBD::Signal2<int,std::string,std::vector<std::string> > AmbiguousFileName;
 
+	void existence_check ();
 	virtual void prevent_deletion ();
 
 protected:

libs/ardour/coreaudiosource.cc

@@ -28,6 +28,8 @@
 #include <appleutility/CAAudioFile.h>
 #include <appleutility/CAStreamBasicDescription.h>
 
+#include <glibmm/fileutils.h>
+
 #include "i18n.h"
 
 #include <AudioToolbox/AudioFormat.h>
@@ -36,21 +38,32 @@ using namespace std;
 using namespace ARDOUR;
 using namespace PBD;
 
+/** Create a new CoreAudioSource using session state, which implies that the
+ *  file must already exist.
+ */
 CoreAudioSource::CoreAudioSource (Session& s, const XMLNode& node)
 	: Source (s, node)
 	, AudioFileSource (s, node)
 {
 	init_cafile ();
+
+        assert (Glib::file_test (_path, Glib::FILE_TEST_EXISTS));
+	existence_check ();
 }
 
+/** Create a new CoreAudioSource from an existing file. Sources created with this
+ *  method are never writable or removable.
+ */
 CoreAudioSource::CoreAudioSource (Session& s, const string& path, int chn, Flag flags)
-	/* files created this way are never writable or removable */
 	: Source (s, DataType::AUDIO, path, Source::Flag (flags & ~(Writable|Removable|RemovableIfEmpty|RemoveAtDestroy))),
 		AudioFileSource (s, path,
 			Source::Flag (flags & ~(Writable|Removable|RemovableIfEmpty|RemoveAtDestroy)))
 {
 	_channel = chn;
 	init_cafile ();
+
+        assert (Glib::file_test (_path, Glib::FILE_TEST_EXISTS));
+	existence_check ();
 }
 
 void

libs/ardour/file_source.cc

@@ -62,8 +62,6 @@ FileSource::FileSource (Session& session, DataType type, const string& path, con
         , _open (false)
 {
 	set_within_session_from_path (path);
-
-        prevent_deletion ();
 }
 
 FileSource::FileSource (Session& session, const XMLNode& node, bool /*must_exist*/)
@@ -77,29 +75,28 @@ FileSource::FileSource (Session& session, const XMLNode& node, bool /*must_exist
 
 	_path = _name;
 	_within_session = true;
-
-        prevent_deletion ();
 }
 
 FileSource::~FileSource()
 {
 }
 
+void
+FileSource::existence_check ()
+{
+        if (Glib::file_test (_path, Glib::FILE_TEST_EXISTS)) {
+		prevent_deletion ();
+	}
+}
+
 void
 FileSource::prevent_deletion ()
 {
-        /* if this file already exists, it cannot be removed, ever
+	if (!(_flags & Destructive)) {
-         */
+		mark_immutable ();
-
+	} else {
-        if (Glib::file_test (_path, Glib::FILE_TEST_EXISTS)) {
+		_flags = Flag (_flags & ~(Removable|RemovableIfEmpty|RemoveAtDestroy));
-		cerr << " ... " << _path << " already  exists, marking immutable\n";
+	}
-
-                if (!(_flags & Destructive)) {
-                        mark_immutable ();
-                } else {
-                        _flags = Flag (_flags & ~(Removable|RemovableIfEmpty|RemoveAtDestroy));
-                }
-        }
 }
 
 bool

libs/ardour/session.cc

@@ -3470,6 +3470,15 @@ Session::new_audio_source_name (const string& base, uint32_t nchan, uint32_t cha
 				break;
 			}
 
+			/* it is possible that we have the path already
+			 * assigned to a source that has not yet been written
+			 * (ie. the write source for a diskstream). we have to
+			 * check this in order to make sure that our candidate
+			 * path isn't used again, because that can lead to
+			 * two Sources point to the same file with different
+			 * notions of their removability.
+			 */
+
 			string possible_path = Glib::build_filename (spath, buf);
 
 			if (source_by_path (possible_path)) {

libs/ardour/smf_source.cc

@@ -63,9 +63,12 @@ SMFSource::SMFSource (Session& s, const string& path, Source::Flag flags)
 {
 	/* note that origin remains empty */
 
-	if (init(_path, false)) {
+	if (init (_path, false)) {
 		throw failed_constructor ();
 	}
+ 
+        assert (!Glib::file_test (_path, Glib::FILE_TEST_EXISTS));
+	existence_check ();
 
 	/* file is not opened until write */
 
@@ -94,10 +97,13 @@ SMFSource::SMFSource (Session& s, const XMLNode& node, bool must_exist)
 		throw failed_constructor ();
 	}
 
-	if (init(_path, true)) {
+	if (init (_path, true)) {
 		throw failed_constructor ();
 	}
 
+        assert (Glib::file_test (_path, Glib::FILE_TEST_EXISTS));
+	existence_check ();
+
 	if (open(_path)) {
 		throw failed_constructor ();
 	}

libs/ardour/sndfilesource.cc

@@ -31,6 +31,7 @@
 #ifdef PLATFORM_WINDOWS
 #include <glibmm/convert.h>
 #endif
+#include <glibmm/fileutils.h>
 #include <glibmm/miscutils.h>
 
 #include "ardour/sndfilesource.h"
@@ -57,9 +58,18 @@ const Source::Flag SndFileSource::default_writable_flags = Source::Flag (
 SndFileSource::SndFileSource (Session& s, const XMLNode& node)
 	: Source(s, node)
 	, AudioFileSource (s, node)
+	, _descriptor (0)
+	, _broadcast_info (0)
+	, _capture_start (false)
+	, _capture_end (false)
+	, file_pos (0)
+	, xfade_buf (0)
 {
 	init_sndfile ();
 
+        assert (Glib::file_test (_path, Glib::FILE_TEST_EXISTS));
+	existence_check ();
+
 	if (open()) {
 		throw failed_constructor ();
 	}
@@ -72,11 +82,20 @@ SndFileSource::SndFileSource (Session& s, const string& path, int chn, Flag flag
 	: Source(s, DataType::AUDIO, path, flags)
           /* note that the origin of an external file is itself */
 	, AudioFileSource (s, path, Flag (flags & ~(Writable|Removable|RemovableIfEmpty|RemoveAtDestroy)))
+	, _descriptor (0)
+	, _broadcast_info (0)
+	, _capture_start (false)
+	, _capture_end (false)
+	, file_pos (0)
+	, xfade_buf (0)
 {
 	_channel = chn;
 
 	init_sndfile ();
 
+        assert (Glib::file_test (_path, Glib::FILE_TEST_EXISTS));
+	existence_check ();
+
 	if (open()) {
 		throw failed_constructor ();
 	}
@@ -89,11 +108,20 @@ SndFileSource::SndFileSource (Session& s, const string& path, const string& orig
                               SampleFormat sfmt, HeaderFormat hf, framecnt_t rate, Flag flags)
 	: Source(s, DataType::AUDIO, path, flags)
 	, AudioFileSource (s, path, origin, flags, sfmt, hf)
+	, _descriptor (0)
+	, _broadcast_info (0)
+	, _capture_start (false)
+	, _capture_end (false)
+	, file_pos (0)
+	, xfade_buf (0)
 {
 	int fmt = 0;
 
         init_sndfile ();
 
+        assert (!Glib::file_test (_path, Glib::FILE_TEST_EXISTS));
+	existence_check ();
+
 	_file_is_new = true;
 
 	switch (hf) {
@@ -160,24 +188,12 @@ SndFileSource::SndFileSource (Session& s, const string& path, const string& orig
 void
 SndFileSource::init_sndfile ()
 {
-	string file;
-
-        _descriptor = 0;
-
-	// lets try to keep the object initalizations here at the top
-	xfade_buf = 0;
-	_broadcast_info = 0;
-
 	/* although libsndfile says we don't need to set this,
 	   valgrind and source code shows us that we do.
 	*/
 
 	memset (&_info, 0, sizeof(_info));
 
-	_capture_start = false;
-	_capture_end = false;
-	file_pos = 0;
-
 	if (destructive()) {
 		xfade_buf = new Sample[xfade_frames];
 		_timeline_position = header_position_offset;