NSAppleScript crash on executeAndReturnError

FROM : James J. Merkel
DATE : Sun Nov 28 21:58:14 2004

I have playing with a method to get  the comment from the Finder's Get
Info window as follows:

-(void)checkFinderCommentsForFile:theFile{
/* Need to use Applescript to read or write Finder Get Info Comments */

/* Convert POSIX path string to hfs path string */
NSURL * urlWithPOSIXPath = [NSURL fileURLWithPath:theFile];
NSString * hfsStylePathString = (NSString
*)CFURLCopyFileSystemPath((CFURLRef)urlWithPOSIXPath,
kCFURLHFSPathStyle);

NSString *appleScriptString = @"tell application \"Finder\"\r get
comment of file ";
appleScriptString = [appleScriptString stringByAppendingString:@"\""];
appleScriptString = [appleScriptString
stringByAppendingString:hfsStylePathString];
appleScriptString = [appleScriptString stringByAppendingString:@"\""];
appleScriptString = [appleScriptString stringByAppendingString:@"\r end
tell\r"];

NSLog(appleScriptString);

NSString *finderComment;

NSAppleScript *theScript = [[NSAppleScript alloc]
initWithSource:appleScriptString];

NSDictionary *theError = [[NSDictionary alloc] init];

finderComment = [[theScript executeAndReturnError: &theError]
stringValue];
NSLog(@"Finder comment is %@.\n", finderComment);

NSLog([theError description]);

[theScript release];
[theError release];
}

This works fine provided the file in the line:
appleScriptString = [appleScriptString
stringByAppendingString:hfsStylePathString];
is a valid path.

However if I comment out the above line to simulate a null file name, I
get the errors:
    NSAppleScriptErrorBriefMessage = "Can't get comment of file \"\".";
    NSAppleScriptErrorMessage = "Finder got an error: Can't get comment
of file \"\".";
    NSAppleScriptErrorNumber = -1728;
    NSAppleScriptErrorRange = <0000001f 00000007 >;

which I would expect, but the application also (sometimes) crashes.
I would have expected that, since an error was detected, a crash would
not occur.
Is this a bug in NSAppleScript. or am I doing something else wrong?

TIA,
Jim Merkel