Fix crash if you tried to remove non-existent credentials from the keychain store

@@ -2279,15 +2279,19 @@ static BOOL isiPhoneOS2;
 + (void)removeCredentialsForHost:(NSString *)host port:(int)port protocol:(NSString *)protocol realm:(NSString *)realm
 {
 	NSURLProtectionSpace *protectionSpace = [[[NSURLProtectionSpace alloc] initWithHost:host port:port protocol:protocol realm:realm authenticationMethod:NSURLAuthenticationMethodDefault] autorelease];
-	NSURLCredentialStorage *storage = [NSURLCredentialStorage sharedCredentialStorage];
-	[storage removeCredential:[storage defaultCredentialForProtectionSpace:protectionSpace] forProtectionSpace:protectionSpace];
+	NSURLCredential *credential = [[NSURLCredentialStorage sharedCredentialStorage] defaultCredentialForProtectionSpace:protectionSpace];
+	if (credential) {
+		[[NSURLCredentialStorage sharedCredentialStorage] removeCredential:credential forProtectionSpace:protectionSpace];
+	}
 }
 
 + (void)removeCredentialsForProxy:(NSString *)host port:(int)port realm:(NSString *)realm
 {
 	NSURLProtectionSpace *protectionSpace = [[[NSURLProtectionSpace alloc] initWithProxyHost:host port:port type:NSURLProtectionSpaceHTTPProxy realm:realm authenticationMethod:NSURLAuthenticationMethodDefault] autorelease];
-	NSURLCredentialStorage *storage = [NSURLCredentialStorage sharedCredentialStorage];
-	[storage removeCredential:[storage defaultCredentialForProtectionSpace:protectionSpace] forProtectionSpace:protectionSpace];
+	NSURLCredential *credential = [[NSURLCredentialStorage sharedCredentialStorage] defaultCredentialForProtectionSpace:protectionSpace];
+	if (credential) {
+		[[NSURLCredentialStorage sharedCredentialStorage] removeCredential:credential forProtectionSpace:protectionSpace];
+	}
 }
 
 

@@ -23,6 +23,7 @@
 - (void)testDownloadProgress;
 - (void)testUploadProgress;
 - (void)testCookies;
+- (void)testRemoveCredentialsFromKeychain;
 - (void)testBasicAuthentication;
 - (void)testDigestAuthentication;
 - (void)testNTLMHandshake;
@@ -40,4 +41,5 @@
 - (void)testThrottlingDownloadBandwidth;
 - (void)testThrottlingUploadBandwidth;
 - (void)testMainThreadDelegateAuthenticationFailure;
+
 @end

@@ -461,6 +461,14 @@
 	GHAssertTrue(success,@"Cookie presented to the server when it should have been removed");
 }
 
+// Test fix for a crash if you tried to remove credentials that didn't exist
+- (void)testRemoveCredentialsFromKeychain
+{
+	[ASIHTTPRequest removeCredentialsForHost:@"apple.com" port:0 protocol:@"http" realm:@"Nothing to see here"];
+	[ASIHTTPRequest removeCredentialsForProxy:@"apple.com" port:0 realm:@"Nothing to see here"];
+	
+}
+
 
 - (void)testBasicAuthentication
 {