Enhance ios native error handling

src/ios/RNFetchBlob.xcodeproj/project.pbxproj

 		A166D1AA1CE0647A00273590 /* RNFetchBlob.h in Sources */ = {isa = PBXBuildFile; fileRef = A15C30111CD25C330074CB35 /* RNFetchBlob.h */; };
 /* End PBXBuildFile section */
 
-/* Begin PBXContainerItemProxy section */
-		A1BAA89E1CF415DF003A9374 /* PBXContainerItemProxy */ = {
-			isa = PBXContainerItemProxy;
-			containerPortal = ADC1D945EE804D3DA47CF622 /* RNFetchBlob.xcodeproj */;
-			proxyType = 2;
-			remoteGlobalIDString = A15C300E1CD25C330074CB35;
-			remoteInfo = RNFetchBlob;
-		};
-/* End PBXContainerItemProxy section */
-
 /* Begin PBXCopyFilesBuildPhase section */
 		A15C300C1CD25C330074CB35 /* CopyFiles */ = {
 			isa = PBXCopyFilesBuildPhase;
 		A15C300E1CD25C330074CB35 /* libRNFetchBlob.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = libRNFetchBlob.a; sourceTree = BUILT_PRODUCTS_DIR; };
 		A15C30111CD25C330074CB35 /* RNFetchBlob.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; name = RNFetchBlob.h; path = RNFetchBlob/RNFetchBlob.h; sourceTree = "<group>"; };
 		A15C30131CD25C330074CB35 /* RNFetchBlob.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; name = RNFetchBlob.m; path = RNFetchBlob/RNFetchBlob.m; sourceTree = "<group>"; };
-		ADC1D945EE804D3DA47CF622 /* RNFetchBlob.xcodeproj */ = {isa = PBXFileReference; explicitFileType = undefined; fileEncoding = 9; includeInIndex = 0; lastKnownFileType = "wrapper.pb-project"; name = RNFetchBlob.xcodeproj; path = "../../node_modules/react-native-fetch-blob/ios/RNFetchBlob.xcodeproj"; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
 		8BD9ABDFAF76406291A798F2 /* Libraries */ = {
 			isa = PBXGroup;
 			children = (
-				ADC1D945EE804D3DA47CF622 /* RNFetchBlob.xcodeproj */,
 			);
 			name = Libraries;
 			sourceTree = "<group>";
 			name = Products;
 			sourceTree = "<group>";
 		};
-		A1BAA8981CF415DF003A9374 /* Products */ = {
-			isa = PBXGroup;
-			children = (
-				A1BAA89F1CF415DF003A9374 /* libRNFetchBlob.a */,
-			);
-			name = Products;
-			sourceTree = "<group>";
-		};
 /* End PBXGroup section */
 
 /* Begin PBXNativeTarget section */
 			mainGroup = A15C30051CD25C330074CB35;
 			productRefGroup = A15C300F1CD25C330074CB35 /* Products */;
 			projectDirPath = "";
-			projectReferences = (
-				{
-					ProductGroup = A1BAA8981CF415DF003A9374 /* Products */;
-					ProjectRef = ADC1D945EE804D3DA47CF622 /* RNFetchBlob.xcodeproj */;
-				},
-			);
 			projectRoot = "";
 			targets = (
 				A15C300D1CD25C330074CB35 /* RNFetchBlob */,
 		};
 /* End PBXProject section */
 
-/* Begin PBXReferenceProxy section */
-		A1BAA89F1CF415DF003A9374 /* libRNFetchBlob.a */ = {
-			isa = PBXReferenceProxy;
-			fileType = archive.ar;
-			path = libRNFetchBlob.a;
-			remoteRef = A1BAA89E1CF415DF003A9374 /* PBXContainerItemProxy */;
-			sourceTree = BUILT_PRODUCTS_DIR;
-		};
-/* End PBXReferenceProxy section */
-
 /* Begin PBXSourcesBuildPhase section */
 		A15C300A1CD25C330074CB35 /* Sources */ = {
 			isa = PBXSourcesBuildPhase;

src/ios/RNFetchBlob/RNFetchBlob.m

 
 // request complete
 - (void) connectionDidFinishLoading:(NSURLConnection *)connection {
-    NSData * data = [NSData dataWithData:respData];
+    
+    NSData * data;
+    if(respData != nil)
+        data = [NSData dataWithData:respData];
+    else
+        data = [[NSData alloc] init];
+    
     callback(@[[NSNull null], [data base64EncodedStringWithOptions:0]]);
 }
 
             NSString * name = [field valueForKey:@"name"];
             NSString * content = [field valueForKey:@"data"];
             // field is a text field
-            if([field valueForKey:@"filename"] == nil) {
+            if([field valueForKey:@"filename"] == nil || content == [NSNull null]) {
                 [postData appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
                 [postData appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n", name] dataUsingEncoding:NSUTF8StringEncoding]];
                 [postData appendData:[[NSString stringWithFormat:@"Content-Type: text/plain\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
     // if method is POST or PUT, convert data string format
     if([[method lowercaseString] isEqualToString:@"post"] || [[method lowercaseString] isEqualToString:@"put"]) {
         
-        // generate octet-stream body
-        NSData* blobData = [[NSData alloc] initWithBase64EncodedString:body options:0];
-        NSMutableData* postBody = [[NSMutableData alloc] init];
-        [postBody appendData:[NSData dataWithData:blobData]];
-        [request setHTTPBody:postBody];
-        [mheaders setValue:@"application/octet-stream" forKey:@"content-type"];
-        
+        if(body != nil) {
+            // generate octet-stream body
+            NSData* blobData = [[NSData alloc] initWithBase64EncodedString:body options:0];
+            NSMutableData* postBody = [[NSMutableData alloc] init];
+            [postBody appendData:[NSData dataWithData:blobData]];
+            [request setHTTPBody:postBody];
+            [mheaders setValue:@"application/octet-stream" forKey:@"content-type"];
+        }
     }
     
     [request setHTTPMethod: method];