Preserve version control dictionaries on save

Sources/VLDocument.h

@@ -24,6 +24,7 @@
 	NSString *		songGroove;
 	NSNumber *		songTempo;
 	NSString *		tmpPath;
+	NSFileWrapper *	vcsWrapper;
 
 	VLSheetWindow *	sheetWin;
 	VLLogWindow *	logWin;

Sources/VLDocument.mm

@@ -34,6 +34,7 @@
 		pdfWin				= nil;	
 		logWin				= nil;
 		tmpPath				= nil;
+		vcsWrapper			= nil;
     }
     return self;
 }
@@ -47,6 +48,7 @@
 	[songLyricist release];
 	[songComposer release];
 	[songArranger release];
+	[vcsWrapper release];
 	
 	if (tmpPath) {
 		[[NSFileManager defaultManager] removeFileAtPath:tmpPath handler:nil];
@@ -190,6 +192,30 @@
 				  stringByAppendingPathExtension:extension]];
 }
 
+- (BOOL)saveToURL:(NSURL *)absoluteURL ofType:(NSString *)typeName forSaveOperation:(NSSaveOperationType)saveOperation error:(NSError **)outError
+{
+	NSFileWrapper * preservedVCSWrapper = nil;
+	switch (saveOperation) {
+	case NSSaveToOperation:
+	case NSAutosaveOperation:
+		preservedVCSWrapper = vcsWrapper;
+		[preservedVCSWrapper retain];
+		// Fall through
+	case NSSaveAsOperation:
+		[vcsWrapper release];
+		vcsWrapper = nil;
+		// Fall through
+	case NSSaveOperation:
+		break;
+	}
+	BOOL res = [super saveToURL:absoluteURL ofType:typeName
+					  forSaveOperation:saveOperation error:outError];
+	if (!vcsWrapper)
+		vcsWrapper = preservedVCSWrapper;
+	
+	return res;
+}
+
 - (NSFileWrapper *)fileWrapperOfType:(NSString *)typeName error:(NSError **)outError
 {
 	if ([typeName isEqual:@"VLNativeType"]) {

Sources/VLXMLDocument.mm

@@ -300,6 +300,8 @@ const char * sSteps = "C DbD EbE F GbG AbA BbB ";
 									  autorelease];
 		[wrap addRegularFileWithContents:contents
 			  preferredFilename:@"Song"];
+		if (vcsWrapper)
+			[wrap addFileWrapper:vcsWrapper];
 
 		return wrap;
 	}
@@ -456,8 +458,13 @@ int8_t sStepToPitch[] = {
 
 - (BOOL)readFromXMLFileWrapper:(NSFileWrapper *)wrapper error:(NSError **)outError
 {
-	return [self readFromXMLData: [[[wrapper fileWrappers] objectForKey:@"Song"]
-									  regularFileContents]	
+	NSDictionary * wrappers = [wrapper fileWrappers];
+	if ((vcsWrapper = [wrappers objectForKey:@"CVS"])
+     || (vcsWrapper = [wrappers objectForKey:@".svn"])
+	)
+		[vcsWrapper retain];
+	return [self readFromXMLData:
+					 [[wrappers objectForKey:@"Song"] regularFileContents]	
 				 error:outError];
 }