chriskau/TouchDB-iOS — comment on commit 9cf5a4ca8ebeb7164d7147fc5c93d98bcac8e6e1
File: Source/ChangeTracker/TDChangeTracker.m line 74
By snej:

Both of these strings need to be URL-escaped. (Including the '&' char!) The way to do that is:

CFURLCreateStringByAddingPercentEscapes(NULL,
(CFStringRef)str,
NULL, (CFStringRef)@"&",
kCFStringEncodingUTF8);

Additionally, I believe the parameter value is supposed to be JSON. That means 'obj' should be run through NSJSONSerialization to convert it to NSData, then expanded into an NSString, before being fed into the above call.