EXC_BAD_ACCESS on iOS 6 but not 5 when changing bytes of a CFDataRef
cfdata, core-foundation, exc-bad-access, ios, ios6
Solution
This solves the problem: http://www.iphonedevsdk.com/forum/iphone-sdk-development/108072-exc_bad_access-in-ios-6-but-not-in-ios-5.html
In iOS 6 you need to use `CFDataCreateMutableCopy()` (instead of `CGDataProviderCopyData()`), followed by `CFDataGetMutableBytePtr()` (instead of `CFDataGetBytePtr()`) if you're going to be manipulating the data's bytes directly.
Problem
I have an application that applies various filters to an image. It works great on iOS 5 but crashes on 6. Below is a sample of where it's crashing: ``` CGImageRef inImage = self.CGImage; CFDataRef m_DataRef = CGDataProviderCopyData(CGImageGetDataProvider(inImage)); UInt8 * m_PixelBuf = (UInt8 *) CFDataGetBytePtr(m_DataRef); int length = CFDataGetLength(m_DataRef); for (int i=0; i<length; i+=4) { if(filter == filterCurve){ int r = i; int g = i+1; int b = i+2; int red = m_PixelBuf[r]; int green = m_PixelBuf[g]; int blue = m_PixelBuf[b]; m_PixelBuf[r] = SAFECOLOR(red); // <==== EXC_BAD_ACCESS (code = 2) m_PixelBuf[g] = SAFECOLOR(green); m_PixelBuf[b] = SAFECOLOR(blue); } } ``` Notice the bad access point when I try to assign a value back to `m_PixelBuf`. Anybody have any idea why this is occuring? What in iOS 6 would cause this?