Return nil instead of NO.
Fixes:
error: initialization of pointer of type 'ArrayNode *' to null from a constant boolean expression [-Werror,-Wbool-conversion]
https://github.com/arqbackup/arq_restore/commit/0f0c956e1636ee501369cc04f59f2075b709e0e3
--- ArqRestoreCommand.m.orig
+++ ArqRestoreCommand.m
@@ -610,7 +610,7 @@ - (BOOL)clearCache:(NSArray *)args error:(NSError **)error {
 - (BackupSet *)backupSetForTarget:(Target *)theInitialTarget computerUUID:(NSString *)theComputerUUID error:(NSError **)error {
     NSArray *expandedTargetList = [self expandedTargetListForTarget:theInitialTarget error:error];
     if (expandedTargetList == nil) {
-        return NO;
+        return nil;
     }
     
     for (Target *theTarget in expandedTargetList) {
@@ -622,7 +622,7 @@ - (BackupSet *)backupSetForTarget:(Target *)theInitialTarget computerUUID:(NSStr
             } else {
                 HSLogError(@"error getting backup sets for %@: %@", theTarget, myError);
                 SETERRORFROMMYERROR;
-                return NO;
+                return nil;
             }
         } else {
             for (BackupSet *backupSet in backupSets) {
--- cocoastack/crypto/SHA1Hash.m.orig
+++ cocoastack/crypto/SHA1Hash.m
@@ -68,7 +68,7 @@ + (NSString *)hashFile:(NSString *)path error:(NSError **)error {
         int errnum = errno;
         HSLogError(@"lstat(%@) error %d: %s", path, errnum, strerror(errnum));
         SETNSERROR(@"UnixErrorDomain", errnum, @"%@: %s", path, strerror(errnum));
-        return NO;
+        return nil;
     }
     unsigned long long length = (unsigned long long)st.st_size;
     FileInputStream *fis = [[FileInputStream alloc] initWithPath:path offset:0 length:length];
--- cocoastack/plist/XMLPListReader.m.orig
+++ cocoastack/plist/XMLPListReader.m
@@ -109,7 +109,7 @@ - (ArrayNode *)readArray:(NSXMLNode *)elem error:(NSError **)error {
             id <PListNode> node = [self makeNode:childNode error:error];
             if (!node) {
                 [nodes release];
-                return NO;
+                return nil;
             }
 			[nodes addObject:node];
 		}
@@ -134,7 +134,7 @@ - (DictNode *)readDict:(NSXMLNode *)elem error:(NSError **)error {
             } else {
                 id <PListNode> node = [self makeNode:childNode error:error];
                 if (!node) {
-                    return NO;
+                    return nil;
                 }
 				NSAssert(key != nil, @"must have key before adding value");
 				[dn put:node forKey:key];
--- cocoastack/remotefs/LocalItemFS.m.orig
+++ cocoastack/remotefs/LocalItemFS.m
@@ -161,7 +161,7 @@ - (Item *)createDirectoryWithName:(NSString *)theName inDirectoryItem:(Item *)th
             int errnum = errno;
             HSLogError(@"chown(%@) error %d: %s", thePath, errnum, strerror(errnum));
             SETNSERROR(@"UnixErrorDomain", errnum, @"failed to change ownership of %@: %s", thePath, strerror(errnum));
-            return NO;
+            return nil;
         }
     }
     
@@ -200,14 +200,14 @@ - (Item *)createFileWithData:(NSData *)theData name:(NSString *)theName inDirect
     if (![self ensureTempDirExists:&myError]) {
         SETERRORFROMMYERROR;
         HSLogError(@"error ensuring temp dir %@ exists: %@", tempDir, myError);
-        return NO;
+        return nil;
     }
     
     NSString *tempPath = [tempDir stringByAppendingPathComponent:[NSString stringWithRandomUUID]];
     if (![theData writeToFile:tempPath options:NSAtomicWrite error:&myError]) {
         SETERRORFROMMYERROR;
         HSLogError(@"error creating temp file %@: %@", tempPath, myError);
-        return NO;
+        return nil;
     }
     
     if (![[NSFileManager defaultManager] ensureParentPathExistsForPath:theFullPath targetUID:[[CacheOwnership sharedCacheOwnership] uid] targetGID:[[CacheOwnership sharedCacheOwnership] gid] error:error]) {
@@ -217,21 +217,21 @@ - (Item *)createFileWithData:(NSData *)theData name:(NSString *)theName inDirect
         if (![myError isErrorWithDomain:NSCocoaErrorDomain code:NSFileWriteFileExistsError]) {
             SETERRORFROMMYERROR;
             HSLogError(@"error renaming %@ to %@: %@", tempPath, theFullPath, myError);
-            return NO;
+            return nil;
         }
         // Delete the file that's in the way.
         HSLogDebug(@"deleting existing file before overwriting: %@", theFullPath);
         if (![[NSFileManager defaultManager] removeItemAtPath:theFullPath error:&myError]) {
             SETERRORFROMMYERROR;
             HSLogError(@"error removing a file that's in the way (%@): %@", theFullPath, myError);
-            return NO;
+            return nil;
         }
         // Try again.
         if (![[NSFileManager defaultManager] moveItemAtPath:tempPath toPath:theFullPath error:&myError]) {
             if (![myError isErrorWithDomain:NSCocoaErrorDomain code:NSFileWriteFileExistsError]) {
                 SETERRORFROMMYERROR;
                 HSLogError(@"error renaming %@ to %@: %@", tempPath, theFullPath, myError);
-                return NO;
+                return nil;
             }
         }
     }
@@ -246,7 +246,7 @@ - (Item *)createFileWithData:(NSData *)theData name:(NSString *)theName inDirect
             int errnum = errno;
             HSLogError(@"chown(%@) error %d: %s", theFullPath, errnum, strerror(errnum));
             SETNSERROR(@"UnixErrorDomain", errnum, @"failed to change ownership of %@: %s", theFullPath, strerror(errnum));
-            return NO;
+            return nil;
         }
     }
     Item *item = [[[Item alloc] init] autorelease];
--- cocoastack/s3/S3Lister.m.orig
+++ cocoastack/s3/S3Lister.m
@@ -237,14 +237,14 @@ - (NSArray *)parseXMLResponse:(NSData *)response foundPrefixes:(NSArray **)found
     if (!xmlDoc) {
         HSLogDebug(@"list Objects XML data: %@", [[[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding] autorelease]);
         SETNSERROR([S3Service errorDomain], [myError code], @"error parsing List Objects XML response: %@", myError);
-        return NO;
+        return nil;
     }
     NSXMLElement *rootElement = [xmlDoc rootElement];
     NSArray *isTruncatedNodes = [rootElement nodesForXPath:@"//ListBucketResult/IsTruncated" error:&myError];
     if (isTruncatedNodes == nil) {
         HSLogError(@"nodesForXPath: %@", myError);
         SETERRORFROMMYERROR;
-        return NO;
+        return nil;
     }
     if ([isTruncatedNodes count] == 0) {
         isTruncated = NO;
@@ -256,7 +256,7 @@ - (NSArray *)parseXMLResponse:(NSData *)response foundPrefixes:(NSArray **)found
         if (error != NULL) {
             HSLogError(@"error getting //ListBucketResult/CommonPrefixes/Prefix nodes: %@", *error);
         }
-        return NO;
+        return nil;
     }
     NSMutableArray *theFoundPrefixes = [NSMutableArray array];
     for (NSXMLNode *prefixNode in prefixNodes) {
--- cocoastack/shared/LZ4Compressor.m.orig
+++ cocoastack/shared/LZ4Compressor.m
@@ -67,7 +67,7 @@ - (NSData *)lz4Inflate:(NSData *)data error:(NSError **)error {
 - (NSData *)lockedLZ4Deflate:(NSData *)data error:(NSError **)error {
     if ([data length] > (NSUInteger)INT_MAX) {
         SETNSERROR([self errorDomain], -1, @"length larger than INT_MAX");
-        return NO;
+        return nil;
     }
     
     int originalSize = (int)[data length];
@@ -83,7 +83,7 @@ - (NSData *)lockedLZ4Deflate:(NSData *)data error:(NSError **)error {
     if (compressed == 0) {
         SETNSERROR([self errorDomain], -1, @"LZ4_compress_default failed");
         free(outBuf);
-        return NO;
+        return nil;
     }
     uint32_t nboSize = OSSwapHostToBigInt32(originalSize);
     memcpy(outBuf, &nboSize, 4);
--- glacierrestore/GlacierPackIndex.m.orig
+++ glacierrestore/GlacierPackIndex.m
@@ -327,7 +327,7 @@ - (PackIndexEntry *)doEntryForSHA1:(NSString *)sha1 error:(NSError **)error {
     close(fd);
     if (endIndex == 0) {
         SETNSERROR(@"PacksErrorDomain", ERROR_NOT_FOUND, @"sha1 %@ not found in pack", sha1);
-        return NO;
+        return nil;
     }
     fd = open([localPath fileSystemRepresentation], O_RDONLY);
     if (fd == -1) {
@@ -352,7 +352,7 @@ - (PackIndexEntry *)findEntryForSHA1:(NSString *)sha1 fd:(int)fd betweenStartInd
         int errnum = errno;
         HSLogError(@"mmap(%@) error %d: %s", localPath, errnum, strerror(errnum));
         SETNSERROR(@"UnixErrorDomain", errnum, @"error mapping %@ to memory: %s", localPath, strerror(errnum));
-        return NO;
+        return nil;
     }
     int64_t left = startIndex;
     int64_t right = endIndex - 1;
--- glacierrestore/GlacierPackSet.m.orig
+++ glacierrestore/GlacierPackSet.m
@@ -102,7 +102,7 @@ - (GlacierPackIndex *)glacierPackIndexForObjectSHA1:(NSString *)theObjectSHA1 ta
 }
 - (PackIndexEntry *)packIndexEntryForObjectSHA1:(NSString *)theSHA1 targetConnectionDelegate:(id <TargetConnectionDelegate>)theTCD error:(NSError **)error {
     if (!loadedPIEs && ![self loadPackIndexEntriesWithTargetConnectionDelegate:theTCD error:error]) {
-        return NO;
+        return nil;
     }
     PackIndexEntry *ret = [packIndexEntriesByObjectSHA1 objectForKey:theSHA1];
     if (ret == nil) {
--- glacierrestore/GlacierRestorer.m.orig
+++ glacierrestore/GlacierRestorer.m
@@ -922,12 +922,12 @@ - (NSString *)completedJobIdForArchiveId:(NSString *)theArchiveId error:(NSError
     if ([[NSFileManager defaultManager] fileExistsAtPath:statusPath]) {
         NSDictionary *attribs = [[NSFileManager defaultManager] attributesOfItemAtPath:statusPath error:error];
         if (attribs == nil) {
-            return NO;
+            return nil;
         }
         if ([[attribs objectForKey:NSFileSize] unsignedLongLongValue] > 0) {
             NSData *jobIdData = [NSData dataWithContentsOfFile:statusPath options:NSUncachedRead error:error];
             if (jobIdData == nil) {
-                return NO;
+                return nil;
             }
             ret = [[[NSString alloc] initWithData:jobIdData encoding:NSUTF8StringEncoding] autorelease];
         }
--- repo/ObjectEncryptorV1.m.orig
+++ repo/ObjectEncryptorV1.m
@@ -141,7 +141,7 @@ - (NSString *)sha1HashForV2Data:(NSData *)theData {
 }
 - (NSData *)v2EncryptedObjectFromData:(NSData *)theData masterIV:(NSData *)theMasterIV dataIVAndSymmetricKey:(NSData *)theDataIVAndSymmetricKey error:(NSError **)error {
     SETNSERROR(@"ObjectEncryptorV1", -1, @"writeV2EncryptedObjectFromData not supported");
-    return NO;
+    return nil;
 }
 //
 //- (NSString *)sha1HashForData:(NSData *)theData error:(NSError **)error {
--- repo/ObjectEncryptorV2.m.orig
+++ repo/ObjectEncryptorV2.m
@@ -137,7 +137,7 @@ - (BOOL)ensureDatFileExistsAtTargetWithEncryptionPassword:(NSString *)theEncrypt
 }
 - (NSData *)encryptV1Data:(NSData *)theData error:(NSError **)error {
     SETNSERROR(@"ObjectEncryptorV2ErrorDomain", -1, @"encryptV1Data not supported");
-    return NO;
+    return nil;
 }
 - (NSString *)sha1HashForV2Data:(NSData *)theData {
     // Calculate SHA1 hash of computerUUID+plaintext.
@@ -157,7 +157,7 @@ - (NSData *)v2EncryptedObjectFromData:(NSData *)theData masterIV:(NSData *)theMa
     if (theDataIVAndSymmetricKey != nil) {
         if ([theDataIVAndSymmetricKey length] < DATA_IV_AND_SYMMETRIC_KEY_LEN) {
             SETNSERROR([ObjectEncryptor errorDomain], -1, @"given dataIVAndSymmetricKey is less than %d bytes", DATA_IV_AND_SYMMETRIC_KEY_LEN);
-            return NO;
+            return nil;
         }
         memcpy(dataIVAndSymmetricKey, [theDataIVAndSymmetricKey bytes], DATA_IV_AND_SYMMETRIC_KEY_LEN);
         memcpy(mySymmetricKey, [theDataIVAndSymmetricKey bytes] + IV_LEN, SYMMETRIC_KEY_LEN);
@@ -202,7 +202,7 @@ - (NSData *)v2EncryptedObjectFromData:(NSData *)theData masterIV:(NSData *)theMa
     if (status != kCCSuccess) {
         SETNSERROR([ObjectEncryptor errorDomain], -1, @"encrypt: %@", [self errorMessageForStatus:status]);
         free(outbuf);
-        return NO;
+        return nil;
     }
     
     // Reset theOutBuffer's length.
@@ -213,7 +213,7 @@ - (NSData *)v2EncryptedObjectFromData:(NSData *)theData masterIV:(NSData *)theMa
         if ([theMasterIV length] != IV_LEN) {
             SETNSERROR([ObjectEncryptor errorDomain], -1, @"invalid masterIV length");
             free(outbuf);
-            return NO;
+            return nil;
         }
         memcpy(masterIV, [theMasterIV bytes], IV_LEN);
     } else {
@@ -241,12 +241,12 @@ - (NSData *)v2EncryptedObjectFromData:(NSData *)theData masterIV:(NSData *)theMa
     if (status != kCCSuccess) {
         SETNSERROR([ObjectEncryptor errorDomain], -1, @"encrypt: %@", [self errorMessageForStatus:status]);
         free(outbuf);
-        return NO;
+        return nil;
     }
     if (encryptedMetadataActualLen != ENCRYPTED_DATA_IV_AND_SYMMETRIC_KEY_LEN) {
         SETNSERROR([ObjectEncryptor errorDomain], -1, @"unexpected encrypted metadata length");
         free(outbuf);
-        return NO;
+        return nil;
     }
     
     // Calculate HMACSHA256 of (master IV + encryptedMetadata + ciphertext) using second half of master key.
--- repo/PackSet.m.orig
+++ repo/PackSet.m
@@ -301,7 +301,7 @@ - (BOOL)restorePackForBlobWithSHA1:(NSString *)theSHA1 forDays:(NSUInteger)theDa
 - (NSNumber *)isObjectDownloadableForSHA1:(NSString *)theSHA1 error:(NSError **)error {
     PackIndexEntry *pie = [self packIndexEntryForSHA1:theSHA1 error:error];
     if (pie == nil) {
-        return NO;
+        return nil;
     }
     return [fark isPackDownloadableWithId:[pie packId] storageType:storageType error:error];
 }
--- repo/PackSetDB.m.orig
+++ repo/PackSetDB.m
@@ -387,7 +387,7 @@ - (FMDatabaseQueue *)initDB:(NSError **)error {
     FlockFile *ff = [[[FlockFile alloc] initWithPath:lockFilePath] autorelease];
     __block FMDatabaseQueue *ret = nil;
     if (![ff lockAndExecute:^void() { ret = [self lockedInitDB:error]; } error:error]) {
-        ret = NO;
+        ret = nil;
     }
     return ret;
 }