performed a code review, specifically:

- changed some #include to #import
- fixed some NULL -> nil Cocoa coding conventions
- added new compiler warnings and fixed some warnings they generated
- check for nil from NSTemporaryDirectory
- added missing files to unit test and test app targets
- added xcconfig files for unit test target
- added @Private to some ivars
- changes some variables from signed to unsigned as appropriate
- changed from base 2 to base 10 measurements of file size, consistent with both the actual meaning of metric prefixes and Apple's new policy as of 10.6
- reduced some unneeded copy-paste of code
- fixed failure to check for null from malloc and unneeded check against null before calling free
- OSErr was incorrectly used instead of OSStatus
- added some consts & statics to global strings
- fixed some issues discovered by static analysis
- fixed some 64bit issues, mostly related to casting and the use of slightly incorrect types/sizes
- some dealloc methods were using accessors, changed to access ivars directly, as per Apple guidelines
- removed old NS_DURING, NS_HANDLER, NS_ENDHANDLER macros
- fixed a bug where immutable data was being mutated
- removed all instance of "== YES" as they are dangerous
- removed some redundant nil checks
- fixed some leaks
- conditionally replaced deprecated method usage
- cleanup CF/NSMakeCollectable usage
- fixed bug in GC where memory could be collected too early due to lack of strong references when using UTF8String
- prevent passing null to CFRelease

Author: Sean McBride

Configurations/ConfigCommon.xcconfig

@@ -14,6 +14,7 @@ GCC_DEBUGGING_SYMBOLS = full
 GCC_PRECOMPILE_PREFIX_HEADER = YES
 GCC_PREFIX_HEADER = $(SDKROOT)/System/Library/Frameworks/Cocoa.framework/Headers/Cocoa.h
 GCC_FAST_OBJC_DISPATCH = YES
+GCC_ENABLE_PASCAL_STRINGS = NO
 ARCHS = ppc i386 x86_64
 
 // Enable warnings
@@ -36,4 +37,15 @@ GCC_WARN_UNKNOWN_PRAGMAS = YES
 GCC_WARN_UNUSED_VARIABLE = YES
 GCC_WARN_ABOUT_DEPRECATED_FUNCTIONS = YES
 GCC_WARN_ABOUT_INVALID_OFFSETOF_MACRO = YES
-WARNING_CFLAGS = -Wall
+GCC_WARN_ABOUT_MISSING_PROTOTYPES = YES
+GCC_WARN_HIDDEN_VIRTUAL_FUNCTIONS = YES
+GCC_WARN_ABOUT_INVALID_OFFSETOF_MACRO = YES
+GCC_WARN_UNUSED_FUNCTION = YES
+GCC_WARN_UNUSED_LABEL = YES
+GCC_WARN_UNUSED_VALUE = YES
+GCC_WARN_UNUSED_PARAMETER = YES
+GCC_WARN_ABOUT_MISSING_FIELD_INITIALIZERS = YES
+WARNING_CFLAGS = -Wall -Wundef -Wendif-labels -Wpointer-arith -Wcast-align -Wwrite-strings -Wmissing-noreturn -Wmissing-format-attribute -Wpacked -Wredundant-decls -Winline -Wdisabled-optimization -Wformat=2 -Wlarger-than-32768 -Winvalid-pch
+
+// TODO: 
+// GCC_WARN_UNDECLARED_SELECTOR = YES only 7 warnings

Configurations/ConfigCommonDebug.xcconfig

@@ -3,5 +3,8 @@
 GCC_OPTIMIZATION_LEVEL = 0
 DEBUG_INFORMATION_FORMAT = dwarf
 GCC_GENERATE_DEBUGGING_SYMBOLS = YES
-SPARKLE_EXTRA_DEBUG = -DDEBUG -fstack-protector -D_FORTIFY_SOURCE=2
-OTHER_CFLAGS = $(SPARKLE_EXTRA_DEBUG)
+SPARKLE_EXTRA_DEBUG_10_5_ONLY = -fstack-protector -D_FORTIFY_SOURCE=2
+SPARKLE_EXTRA_DEBUG = -DDEBUG
+OTHER_CFLAGS = $(SPARKLE_EXTRA_DEBUG)
+
+// Add $(SPARKLE_EXTRA_DEBUG_10_5_ONLY) to SPARKLE_EXTRA_DEBUG if your deployment is 10.5 or greater.

Configurations/ConfigUnitTest.xcconfig

@@ -0,0 +1,9 @@
+// Unit Test only
+
+INFOPLIST_FILE = Tests/Sparkle Unit Tests-Info.plist
+OTHER_LDFLAGS = -framework Cocoa -framework SenTestingKit
+PRODUCT_NAME = Sparkle Unit Tests
+WRAPPER_EXTENSION = octest
+FRAMEWORK_SEARCH_PATHS = $(DEVELOPER_LIBRARY_DIR)/Frameworks
+GCC_PREFIX_HEADER = $(SYSTEM_LIBRARY_DIR)/Frameworks/Cocoa.framework/Headers/Cocoa.h
+GCC_PRECOMPILE_PREFIX_HEADER = YES

Configurations/ConfigUnitTestDebug.xcconfig

@@ -0,0 +1,3 @@
+#include "ConfigCommon.xcconfig"
+#include "ConfigCommonDebug.xcconfig"
+#include "ConfigUnitTest.xcconfig"

Configurations/ConfigUnitTestRelease.xcconfig

@@ -0,0 +1,3 @@
+#include "ConfigCommon.xcconfig"
+#include "ConfigCommonRelease.xcconfig"
+#include "ConfigUnitTest.xcconfig"

Configurations/ConfigUnitTestReleaseGCSupport.xcconfig

@@ -0,0 +1,3 @@
+#include "ConfigUnitTestRelease.xcconfig"
+
+GCC_ENABLE_OBJC_GC = required

NTSynchronousTask.h

@@ -11,6 +11,7 @@
 
 @interface NTSynchronousTask : NSObject
 {
+@private
     NSTask *mv_task;
     NSPipe *mv_outputPipe;
     NSPipe *mv_inputPipe;

NTSynchronousTask.m

@@ -56,10 +56,10 @@ - (void)dealloc
 {
 	[[NSNotificationCenter defaultCenter] removeObserver:self];
 
-    [self setTask:nil];
-    [self setOutputPipe:nil];
-    [self setInputPipe:nil];
-	[self setOutput:nil];
+    [mv_task release];
+    [mv_outputPipe release];
+    [mv_inputPipe release];
+	[mv_output release];
 
     [super dealloc];
 }
@@ -70,7 +70,7 @@ + (NSData*)task:(NSString*)toolPath directory:(NSString*)currentDirectory withAr
 	NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
 	NSData* result=nil;
 
-	NS_DURING
+	@try
 	{
 		NTSynchronousTask* task = [[NTSynchronousTask alloc] init];
 
@@ -81,8 +81,7 @@ + (NSData*)task:(NSString*)toolPath directory:(NSString*)currentDirectory withAr
 
 		[task release];
 	}	
-	NS_HANDLER;
-	NS_ENDHANDLER;
+	@catch (NSException *localException) { }
 
 	[pool drain];
 
@@ -92,10 +91,6 @@ + (NSData*)task:(NSString*)toolPath directory:(NSString*)currentDirectory withAr
     return result;
 }
 
-@end
-
-@implementation NTSynchronousTask (Private)
-
 - (void)run:(NSString*)toolPath directory:(NSString*)currentDirectory withArgs:(NSArray*)args input:(NSData*)input;
 {
 	BOOL success = NO;
@@ -118,12 +113,12 @@ - (void)run:(NSString*)toolPath directory:(NSString*)currentDirectory withArgs:(
 
 	[[[self outputPipe] fileHandleForReading] readToEndOfFileInBackgroundAndNotifyForModes:[NSArray arrayWithObjects:NSDefaultRunLoopMode, NSModalPanelRunLoopMode, NSEventTrackingRunLoopMode, nil]];
 
-	NS_DURING
+	@try
+	{
 		[[self task] launch];
 		success = YES;
-	NS_HANDLER
-		;
-	NS_ENDHANDLER
+	}
+	@catch (NSException *localException) { }
 
 	if (success)
 	{

SUAppcast.h

@@ -10,7 +10,9 @@
 #define SUAPPCAST_H
 
 @class SUAppcastItem;
-@interface SUAppcast : NSObject {
+@interface SUAppcast : NSObject
+{
+@private
 	NSArray *items;
 	NSString *userAgentString;
 	id delegate;

SUAppcast.m

@@ -40,8 +40,12 @@ - (void)fetchAppcastFromURL:(NSURL *)url
 
 - (void)download:(NSURLDownload *)download decideDestinationWithSuggestedFilename:(NSString *)filename
 {
-    NSString *destinationFilename = [NSTemporaryDirectory() stringByAppendingPathComponent:filename];
-    [download setDestination:destinationFilename allowOverwrite:NO];
+	NSString* destinationFilename = NSTemporaryDirectory();
+	if (destinationFilename)
+	{
+		destinationFilename = [destinationFilename stringByAppendingPathComponent:filename];
+		[download setDestination:destinationFilename allowOverwrite:NO];
+	}
 }
 
 - (void)download:(NSURLDownload *)download didCreateDestination:(NSString *)path
@@ -52,7 +56,8 @@ - (void)download:(NSURLDownload *)download didCreateDestination:(NSString *)path
 
 - (void)downloadDidFinish:(NSURLDownload *)download
 {
-	CFRelease(download);
+	if (download)
+		CFRelease(download);
 
 	NSError *error = nil;
     NSXMLDocument *document = [[NSXMLDocument alloc] initWithContentsOfURL:[NSURL fileURLWithPath:downloadFilename] options:0 error:&error];
@@ -62,7 +67,7 @@ - (void)downloadDidFinish:(NSURLDownload *)download
 #if MAC_OS_X_VERSION_MIN_REQUIRED <= MAC_OS_X_VERSION_10_4
     [[NSFileManager defaultManager] removeFileAtPath:downloadFilename handler:nil];
 #else
-    [[NSFileManager defaultManager] removeItemAtPath:downloadFilename error:NULL];
+    [[NSFileManager defaultManager] removeItemAtPath:downloadFilename error:nil];
 #endif
     [downloadFilename release];
     downloadFilename = nil;
@@ -179,13 +184,14 @@ - (void)downloadDidFinish:(NSURLDownload *)download
 
 - (void)download:(NSURLDownload *)download didFailWithError:(NSError *)error
 {
-	CFRelease(download);
+	if (download)
+		CFRelease(download);
 	if (downloadFilename)
 	{
 #if MAC_OS_X_VERSION_MIN_REQUIRED <= MAC_OS_X_VERSION_10_4
 		[[NSFileManager defaultManager] removeFileAtPath:downloadFilename handler:nil];
 #else
-		[[NSFileManager defaultManager] removeItemAtPath:downloadFilename error:NULL];
+		[[NSFileManager defaultManager] removeItemAtPath:downloadFilename error:nil];
 #endif
 	}
     [downloadFilename release];
@@ -219,7 +225,7 @@ - (NSXMLNode *)bestNodeInNodes:(NSArray *)nodes
     NSXMLElement *node;
     NSMutableArray *languages = [NSMutableArray array];
     NSString *lang;
-    NSInteger i;
+    NSUInteger i;
     while ((node = [nodeEnum nextObject]))
     {
         lang = [[node attributeForName:@"xml:lang"] stringValue];