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