The export code caused an exception when no database was selected but…

… the filename contained the database token (fixes #2145)

Source/SPExportFilenameUtilities.m

@@ -346,15 +346,15 @@ - (NSString *)expandCustomFilenameFormatUsingTableName:(NSString *)table
			NSString *tokenContent = [filenamePart tokenContent];

			if ([tokenContent isEqualToString:NSLocalizedString(@"host", @"export filename host token")]) {
				[string appendString:[tableDocumentInstance host]];
				[string appendStringOrNil:[tableDocumentInstance host]];

			} 
			else if ([tokenContent isEqualToString:NSLocalizedString(@"database", @"export filename database token")]) {
				[string appendString:[tableDocumentInstance database]];
				[string appendStringOrNil:[tableDocumentInstance database]];

			} 
			else if ([tokenContent isEqualToString:NSLocalizedString(@"table", @"table")]) {
				[string appendString:(table) ? table : @""];
				[string appendStringOrNil:table];
			} 
			else if ([tokenContent isEqualToString:NSLocalizedString(@"date", @"export filename date token")]) {
				[dateFormatter setDateStyle:NSDateFormatterShortStyle];
@@ -380,7 +380,7 @@ - (NSString *)expandCustomFilenameFormatUsingTableName:(NSString *)table
				[string appendString:[dateFormatter stringFromDate:[NSDate date]]];
			}
			else if ([tokenContent isEqualToString:NSLocalizedString(@"favorite", @"export filename favorite name token")]) {
				[string appendString:[tableDocumentInstance name]];
				[string appendStringOrNil:[tableDocumentInstance name]];
			}
		} 
		else {

Source/SPNarrowDownCompletion.m

@@ -441,7 +441,7 @@ - (NSString *)tableView:(NSTableView *)aTableView toolTipForCell:(id)aCell rect:
		} else {
			if([[filtered objectAtIndex:rowIndex] objectForKey:@"list"]) {
				NSMutableString *tt = [NSMutableString string];
				[tt appendString:([[filtered objectAtIndex:rowIndex] objectForKey:@"type"]) ? [[filtered objectAtIndex:rowIndex] objectForKey:@"type"] : @""];
				[tt appendStringOrNil:[[filtered objectAtIndex:rowIndex] objectForKey:@"type"]];
				[tt appendString:@"\n"];
				[tt appendString:NSLocalizedString(@"Type Declaration:", @"type declaration header")];
				[tt appendString:@"\n"];

Source/SPStringAdditions.h

@@ -101,3 +101,17 @@ static inline id NSMutableAttributedStringAttributeAtIndex(NSMutableAttributedSt
 */
- (BOOL)nonConsecutivelySearchString:(NSString *)other matchingRanges:(NSArray **)submatches;
@end

@interface NSMutableString (SPStringAdditions)
/**
 * nil-safe variant of setString:
 * nil will be interpreted as @"" instead of throwing an exception
 */
- (void)setStringOrNil:(NSString *)aString;

/**
 * nil-safe variant of appendString: 
 * nil will be interpreted as @"" instead of throwing an exception
 */
- (void)appendStringOrNil:(NSString *)aString;
@end

Source/SPStringAdditions.m

@@ -562,3 +562,17 @@ static NSInteger _smallestOf(NSInteger a, NSInteger b, NSInteger c)

	return min;
}

@implementation NSMutableString (SPStringAdditions)

- (void)setStringOrNil:(NSString *)aString
{
	[self setString:(aString? aString : @"")];
}

- (void)appendStringOrNil:(NSString *)aString
{
	[self appendString:(aString? aString : @"")];
}

@end