Changed NSString/NSData functions to return empty on error

bindings/objc/mpack/mpack-objc.h

@@ -60,7 +60,7 @@ static NSString* const mpack_nserror_domain = @"com.ludocode.mpack";
  * This does not accept any UTF-8 variant such as Modified UTF-8, CESU-8 or
  * WTF-8. Only pure UTF-8 is allowed.
  *
- * If an error occurs, nil is returned.
+ * If an error occurs, an empty NSString is returned.
  *
  * @param reader The MPack reader
  * @param length The length of the string in bytes
@@ -77,7 +77,7 @@ NSString* mpack_read_nsstring(mpack_reader_t* reader, size_t length);
  * which yielded one of these types, or by a call to an expect function
  * such as mpack_expect_str() or mpack_expect_bin().
  *
- * If an error occurs, nil is returned.
+ * If an error occurs, an empty NSData is returned.
  *
  * This can be called multiple times for a single str, bin or ext
  * to read the data in chunks. The total data read must add up
@@ -96,21 +96,21 @@ NSData* mpack_read_nsdata(mpack_reader_t* reader, size_t count);
  * Reads a UTF-8 string with the given maximum byte size and returns
  * it as an NSString.
  *
+ * If an error occurs, an empty NSString is returned.
+ *
  * @throws mpack_error_too_big If the string is larger than the given maxsize.
  * @throws mpack_error_type If the value is not a string.
- *
- * @return An NSString, or nil if an error occurs.
  */
 NSString* mpack_expect_nsstring(mpack_reader_t* reader, size_t maxsize);
 
 /**
  * Reads a binary blob with the given maximum byte size and returns it
  * as an NSData.
  *
+ * If an error occurs, an empty NSData is returned.
+ *
  * @throws mpack_error_too_big If the data is larger than the given maxsize.
  * @throws mpack_error_type If the value is not a binary blob.
- *
- * @return An NSData, or nil if an error occurs.
  */
 NSData* mpack_expect_bin_nsdata(mpack_reader_t* reader, size_t maxsize);
 #endif
@@ -122,22 +122,22 @@ NSData* mpack_expect_bin_nsdata(mpack_reader_t* reader, size_t maxsize);
  * Returns an NSString representing the contents of this string node with
  * the given maximum byte size, or nil if an error occurs.
  *
+ * If an error occurs, an empty NSString is returned.
+ *
  * @throws mpack_error_too_big If the string is larger than the given maxsize.
  * @throws mpack_error_type If the value is not a string.
- *
- * @return An NSString, or nil if an error occurs.
  */
 NSString* mpack_node_nsstring(mpack_node_t node, size_t maxsize);
 
 /**
  * Returns an NSData representing the contents of this node with the
  * given maximum byte size, or nil if an error occurs.
  *
+ * If an error occurs, an empty NSData is returned.
+ *
  * @throws mpack_error_too_big If the data is larger than the given maxsize.
  * @throws mpack_error_type If the value is not a string, binary blob or
  *     ext type.
- *
- * @return An NSData, or nil if an error occurs.
  */
 NSData* mpack_node_bin_nsdata(mpack_node_t node, size_t maxsize);
 #endif

bindings/objc/mpack/mpack-objc.m

@@ -76,26 +76,26 @@ - (NSString*)localizedDescription {
 
 NSString* mpack_read_nsstring(mpack_reader_t* reader, size_t length) {
     if (mpack_reader_error(reader) != mpack_ok)
-        return nil;
+        return @"";
 
     // small string
     if (mpack_should_read_bytes_inplace(reader, length)) {
         const char* bytes = mpack_read_utf8_inplace(reader, length);
         if (mpack_reader_error(reader) != mpack_ok)
-            return nil;
+            return @"";
         return MPACK_OBJC_AUTORELEASE([[NSString alloc] initWithBytes:(const void*)bytes length:length encoding:NSUTF8StringEncoding]);
     }
 
     // long string
     char* bytes = (char*)mpack_stdlib_malloc(length);
     if (bytes == NULL) {
         mpack_reader_flag_error(reader, mpack_error_memory);
-        return nil;
+        return @"";
     }
 
     mpack_read_utf8(reader, bytes, length);
     if (mpack_reader_error(reader) != mpack_ok)
-        return nil;
+        return @"";
 
     return MPACK_OBJC_AUTORELEASE([[NSString alloc] initWithBytesNoCopy:(void*)bytes
             length:length encoding:NSUTF8StringEncoding freeWhenDone:YES]);
@@ -107,15 +107,15 @@ - (NSString*)localizedDescription {
     if (mpack_should_read_bytes_inplace(reader, count)) {
         const char* bytes = mpack_read_bytes_inplace(reader, count);
         if (mpack_reader_error(reader) != mpack_ok)
-            return nil;
+            return [NSData data];
         return [NSData dataWithBytes:(const void*)bytes length:count];
     }
 
     // big data
     NSMutableData* mdata = [NSMutableData dataWithLength:count];
     mpack_read_bytes(reader, (char*)[mdata mutableBytes], count);
     if (mpack_reader_error(reader) != mpack_ok)
-        return nil;
+        return [NSData data];
     return mdata;
 }
 
@@ -148,12 +148,12 @@ - (NSString*)localizedDescription {
 NSString* mpack_node_nsstring(mpack_node_t node, size_t maxsize) {
     if (mpack_node_strlen(node) > maxsize) {
         mpack_node_flag_error(node, mpack_error_too_big);
-        return nil;
+        return @"";
     }
 
     mpack_node_check_utf8(node);
     if (mpack_node_error(node) != mpack_ok)
-        return nil;
+        return @"";
 
     size_t count = (size_t)node.data->len;
     const char* bytes = node.data->value.bytes;
@@ -164,19 +164,19 @@ - (NSString*)localizedDescription {
 
 NSData* mpack_node_bin_nsdata(mpack_node_t node, size_t maxsize) {
     if (mpack_node_error(node) != mpack_ok)
-        return nil;
+        return [NSData data];
 
     if (node.data->type != mpack_type_bin) {
         mpack_node_flag_error(node, mpack_error_type);
-        return nil;
+        return [NSData data];
     }
 
     size_t count = (size_t)node.data->len;
     const char* bytes = node.data->value.bytes;
 
     if (count > maxsize) {
         mpack_node_flag_error(node, mpack_error_too_big);
-        return nil;
+        return [NSData data];
     }
 
     return [NSData dataWithBytes:(const void*)bytes length:count];