Conversion Between path URLs with certain percent escapes not being removed

FROM : Daniel Brieck Jr.
DATE : Sat Jan 19 04:01:17 2008

Hello all,

I am trying to go from a local URL path  such as "/Volumes/TV%
20SHOWS/" and convert it to "cifs://MSHOME;<email_removed>/TV
%20SHOWS"

Within that conversion I am using FSPathMakeRef() of Files.h which 
does not like to see percent encoded strings passed into it. So I try 
to filter them out and replace them with their character 
representations.

However, the problem occurs with the percent escape in the local URL 
path given above, they are not converted as expected.

I am using the function  CFURLCreateStringByReplacingPercentEscapes() 
of CFURL.h to remove the percent escapes. However with this above 
example it does not appear to be removing the %20 and replacing it 
with a single SPACE.

Also I have tried the 
CFURLCreateStringByReplacingPercentEscapesUsingEncoding() , but have 
only been able to successfully remove %escapes but without replacing 
the characters represented.  See commented out trial below, I have 
tried all the Built-in String Encodings types with no good results of 
replacing the "%20" with a SPACE.

For example this local path  "/Volumes/MSHOME%3BDELLOPTIPLEXGX1/" and 
its %3B a.k.a ";" convert ok and allow the code to run and return a 
result,  but passing in something like this "/Volumes/TV%20SHOWS/" 
causes an assertion check to fail since it is passing in a %-- 
sequence at this point below for the newPath parameter.

   err = FSPathMakeRef( (const UInt8*) newPath, &ref, NULL);
        assert(err == noErr);

It has to be some kind of character encoding interpretation issue, 
any ideas as to what I may be doing wrong would be greatly 
appreciated.  See the Implementation below for the more complete 
picture of the conversion process.

Thank you,
Daniel J. Brieck Jr.
Note: that I am running Mac Os x 10.4.11 (Intel) on Xcode 2.5

The implementation file:

@implementation NSApplication (getServerURL)


- (NSString *) urlStringForServerVolume:(const char *)  path
{
        OSStatus        err;
        FSRef          ref;
        FSCatalogInfo  catInfo;
        CFURLRef        url;
        CFStringRef    str;
        NSString *      result;
        CFStringRef noPercentsPath;
        CFStringRef stPath;
        CFIndex size;
        char* newPath = NULL;

//Testing
        printf("Given path\n");
        printf("%s\n", path);
        printf("end given path\n");

        //Check that the supplied path is not NULL
        assert(path != NULL);

        //Converts the const char * to a CFStringRef
        stPath = CFStringCreateWithCString (kCFAllocatorDefault, 
path, kCFStringEncodingUTF8);
        assert(stPath != NULL);

        //Checking for any percent escape sequences and replacing 
them with their character equivalents
        noPercentsPath = CFURLCreateStringByReplacingPercentEscapes
(kCFAllocatorDefault , stPath, CFSTR(" ") );

        //noPercentsPath = 
CFURLCreateStringByReplacingPercentEscapesUsingEncoding
(kCFAllocatorDefault , stPath, CFSTR(" "), kCFStringEncodingUnicode );


        // Converting from CFStringRef to a UTF8 character encoding
        //size = CFStringGetMaximumSizeForEncoding(CFStringGetLength
(noPercentsPath), kCFStringEncodingUTF8) + 1;
        size = CFStringGetMaximumSizeOfFileSystemRepresentation 
(noPercentsPath);

        newPath = malloc(size);
        if (newPath != NULL)
        {
            printf("This Works\n");
            Boolean testVal = CFStringGetCString (noPercentsPath, 
newPath, size, kCFStringEncodingUTF8);
            //Boolean testVal = CFStringGetCString (noPercentsPath, 
newPath, size, kCFStringEncodingUTF16);
            assert(testVal == 1);
        }

//Testing
        printf("Print Path\n");
        printf("%s\n",newPath);
        printf("END IT\n");

        err = FSPathMakeRef( (const UInt8*) newPath, &ref, NULL);
        assert(err == noErr);



        err = FSGetCatalogInfo(&ref, kFSCatInfoVolume, &catInfo, 
NULL, NULL, NULL);
        assert(err == noErr);
        err = FSCopyURLForVolume(catInfo.volume, &url);
        assert(err == noErr);
        str = CFURLGetString(url);
        assert(str != NULL);
        result = [NSString stringWithString:(NSString *) str];
        assert(result != nil);


        //Free some stuff

        free(newPath); newPath = NULL;
        CFRelease(url);
        CFRelease(noPercentsPath);

        return result;
}

@end