Exclude the default GTMSessionFetcher logs directory from iTunes/iClo…

…ud backups.

If client apps set a custom logs directory, it will continue to be the
responsibility of the client app to exclude that directory from backups.

Source/GTMSessionFetcherLogging.h

@@ -23,12 +23,11 @@
 //
 // to begin generating log files.
 //
-// Log files are put into a folder on the desktop called "GTMHTTPDebugLogs"
-// unless another directory is specified with +setLoggingDirectory.
-//
-// In the iPhone simulator, the default logs location is the user's home
-// directory in ~/Library/Application Support.  On the iPhone device, the
-// default logs location is the application's documents directory on the device.
+// Unless explicitly set by the application using +setLoggingDirectory:,
+// logs are put into a default directory, located at:
+//   * macOS: ~/Desktop/GTMHTTPDebugLogs
+//   * iOS simulator: ~/GTMHTTPDebugLogs (in application sandbox)
+//   * iOS device: ~/Documents/GTMHTTPDebugLogs (in application sandbox)
 //
 // Tip: use the Finder's "Sort By Date" to find the most recent logs.
 //
@@ -54,9 +53,15 @@
 
 @interface GTMSessionFetcher (GTMSessionFetcherLogging)
 
-// Note: the default logs directory is ~/Desktop/GTMHTTPDebugLogs; it will be
-// created as needed.  If a custom directory is set, the directory should
-// already exist.
+// Note: on macOS the default logs directory is ~/Desktop/GTMHTTPDebugLogs; on
+// iOS simulators it will be the ~/GTMHTTPDebugLogs (in the app sandbox); on
+// iOS devices it will be in ~/Documents/GTMHTTPDebugLogs (in the app sandbox).
+// These directories will be created as needed, and are excluded from backups
+// to iCloud and iTunes.
+//
+// If a custom directory is set, the directory should already exist. It is
+// the application's responsibility to exclude any custom directory from
+// backups, if desired.
 + (void)setLoggingDirectory:(NSString *)path;
 + (NSString *)loggingDirectory;
 

Source/GTMSessionFetcherLogging.m

@@ -109,7 +109,13 @@ + (NSString *)loggingDirectory {
                              withIntermediateDirectories:YES
                                               attributes:nil
                                                    error:NULL];
+        if (doesFolderExist) {
+          // The directory has been created. Exclude it from backups.
+          NSURL *pathURL = [NSURL fileURLWithPath:logsFolderPath isDirectory:YES];
+          [pathURL setResourceValue:@YES forKey:NSURLIsExcludedFromBackupKey error:NULL];
+        }
       }
+
       if (doesFolderExist) {
         // it's there; store it in the global
         gLoggingDirectoryPath = [logsFolderPath copy];