Guard against NSError null pointer dereferences

Author: dbeard

ios/CodePush/CodePush.h

@@ -128,7 +128,7 @@ failCallback:(void (^)(NSError *err))failCallback;
 
 + (NSString *)getPackageFolderPath:(NSString *)packageHash;
 
-+ (void)installPackage:(NSDictionary *)updatePackage
++ (BOOL)installPackage:(NSDictionary *)updatePackage
    removePendingUpdate:(BOOL)removePendingUpdate
                  error:(NSError **)error;
 
@@ -153,7 +153,7 @@ failCallback:(void (^)(NSError *err))failCallback;
 
 @interface CodePushUpdateUtils : NSObject
 
-+ (void)copyEntriesInFolder:(NSString *)sourceFolder
++ (BOOL)copyEntriesInFolder:(NSString *)sourceFolder
                  destFolder:(NSString *)destFolder
                       error:(NSError **)error;
 

ios/CodePush/CodePushPackage.m

@@ -293,25 +293,25 @@ + (NSString *)getCodePushPath
 + (NSDictionary *)getCurrentPackage:(NSError **)error
 {
     NSString *packageHash = [CodePushPackage getCurrentPackageHash:error];
-    if (*error || !packageHash) {
+    if (!packageHash) {
         return nil;
     }
-    
+
     return [CodePushPackage getPackage:packageHash error:error];
 }
 
 + (NSString *)getCurrentPackageBundlePath:(NSError **)error
 {
     NSString *packageFolder = [self getCurrentPackageFolderPath:error];
 
-    if(*error) {
-        return NULL;
+    if (!packageFolder) {
+        return nil;
     }
 
     NSDictionary *currentPackage = [self getCurrentPackage:error];
 
-    if(*error) {
-        return NULL;
+    if (!currentPackage) {
+        return nil;
     }
 
     NSString *relativeBundlePath = [currentPackage objectForKey:RelativeBundlePathKey];
@@ -325,7 +325,7 @@ + (NSString *)getCurrentPackageBundlePath:(NSError **)error
 + (NSString *)getCurrentPackageHash:(NSError **)error
 {
     NSDictionary *info = [self getCurrentPackageInfo:error];
-    if (*error || !info) {
+    if (!info) {
         return nil;
     }
 
@@ -336,14 +336,14 @@ + (NSString *)getCurrentPackageFolderPath:(NSError **)error
 {
     NSDictionary *info = [self getCurrentPackageInfo:error];
 
-    if (*error) {
-        return NULL;
+    if (!info) {
+        return nil;
     }
 
     NSString *packageHash = info[@"currentPackage"];
 
     if (!packageHash) {
-        return NULL;
+        return nil;
     }
 
     return [self getPackageFolderPath:packageHash];
@@ -359,15 +359,15 @@ + (NSMutableDictionary *)getCurrentPackageInfo:(NSError **)error
     NSString *content = [NSString stringWithContentsOfFile:statusFilePath
                                                   encoding:NSUTF8StringEncoding
                                                      error:error];
-    if (*error) {
+    if (!content) {
         return nil;
     }
 
     NSData *data = [content dataUsingEncoding:NSUTF8StringEncoding];
     NSDictionary* json = [NSJSONSerialization JSONObjectWithData:data
                                                          options:kNilOptions
                                                            error:error];
-    if (*error) {
+    if (!json) {
         return nil;
     }
 
@@ -392,8 +392,7 @@ + (NSDictionary *)getPackage:(NSString *)packageHash
     NSString *updateMetadataString = [NSString stringWithContentsOfFile:updateMetadataFilePath
                                                                encoding:NSUTF8StringEncoding
                                                                   error:error];
-    
-    if (*error) {
+    if (!updateMetadataString) {
         return nil;
     }
 
@@ -411,7 +410,7 @@ + (NSString *)getPackageFolderPath:(NSString *)packageHash
 + (NSDictionary *)getPreviousPackage:(NSError **)error
 {
     NSString *packageHash = [self getPreviousPackageHash:error];
-    if (*error || !packageHash) {
+    if (!packageHash) {
         return nil;
     }
 
@@ -421,7 +420,7 @@ + (NSDictionary *)getPreviousPackage:(NSError **)error
 + (NSString *)getPreviousPackageHash:(NSError **)error
 {
     NSDictionary *info = [self getCurrentPackageInfo:error];
-    if (*error) {
+    if (!info) {
         return nil;
     }
 
@@ -438,25 +437,25 @@ + (NSString *)getUnzippedFolderPath
     return [[self getCodePushPath] stringByAppendingPathComponent:UnzippedFolderName];
 }
 
-+ (void)installPackage:(NSDictionary *)updatePackage
++ (BOOL)installPackage:(NSDictionary *)updatePackage
    removePendingUpdate:(BOOL)removePendingUpdate
                  error:(NSError **)error
 {
     NSString *packageHash = updatePackage[@"packageHash"];
     NSMutableDictionary *info = [self getCurrentPackageInfo:error];
 
-    if (*error) {
-        return;
+    if (!info) {
+        return NO;
     }
 
     if (packageHash && [packageHash isEqualToString:info[@"currentPackage"]]) {
         // The current package is already the one being installed, so we should no-op.
-        return;
+        return YES;
     }
 
     if (removePendingUpdate) {
         NSString *currentPackageFolderPath = [self getCurrentPackageFolderPath:error];
-        if (!*error && currentPackageFolderPath) {
+        if (currentPackageFolderPath) {
             // Error in deleting pending package will not cause the entire operation to fail.
             NSError *deleteError;
             [[NSFileManager defaultManager] removeItemAtPath:currentPackageFolderPath
@@ -467,7 +466,7 @@ + (void)installPackage:(NSDictionary *)updatePackage
         }
     } else {
         NSString *previousPackageHash = [self getPreviousPackageHash:error];
-        if (!*error && previousPackageHash && ![previousPackageHash isEqualToString:packageHash]) {
+        if (previousPackageHash && ![previousPackageHash isEqualToString:packageHash]) {
             NSString *previousPackageFolderPath = [self getPackageFolderPath:previousPackageHash];
             // Error in deleting old package will not cause the entire operation to fail.
             NSError *deleteError;
@@ -481,31 +480,30 @@ + (void)installPackage:(NSDictionary *)updatePackage
     }
 
     [info setValue:packageHash forKey:@"currentPackage"];
-    
-    [self updateCurrentPackageInfo:info
-                             error:error];
+    return [self updateCurrentPackageInfo:info
+                                    error:error];
 }
 
 + (void)rollbackPackage
 {
     NSError *error;
     NSMutableDictionary *info = [self getCurrentPackageInfo:&error];
-    if (error) {
+    if (!info) {
         CPLog(@"Error getting current package info: %@", error);
         return;
     }
 
-    NSString *currentPackageFolderPath = [self getCurrentPackageFolderPath:&error];
-    if (error) {
+    NSString *currentPackageFolderPath = [self getCurrentPackageFolderPath:&error];        
+    if (!currentPackageFolderPath) {
         CPLog(@"Error getting current package folder path: %@", error);
         return;
     }
 
     NSError *deleteError;
-    [[NSFileManager defaultManager] removeItemAtPath:currentPackageFolderPath
+    BOOL result = [[NSFileManager defaultManager] removeItemAtPath:currentPackageFolderPath
                                                error:&deleteError];
-    if (deleteError) {
-        CPLog(@"Error deleting current package contents at %@", currentPackageFolderPath);
+    if (!result) {
+        CPLog(@"Error deleting current package contents at %@ error %@", currentPackageFolderPath, deleteError);
     }
 
     [info setValue:info[@"previousPackage"] forKey:@"currentPackage"];
@@ -514,18 +512,27 @@ + (void)rollbackPackage
     [self updateCurrentPackageInfo:info error:&error];
 }
 
-+ (void)updateCurrentPackageInfo:(NSDictionary *)packageInfo
++ (BOOL)updateCurrentPackageInfo:(NSDictionary *)packageInfo
                            error:(NSError **)error
 {
     NSData *packageInfoData = [NSJSONSerialization dataWithJSONObject:packageInfo
                                                               options:0
                                                                 error:error];
+    if (!packageInfoData) {
+        return NO;
+    }
+
     NSString *packageInfoString = [[NSString alloc] initWithData:packageInfoData
                                                         encoding:NSUTF8StringEncoding];
-    [packageInfoString writeToFile:[self getStatusFilePath]
+    BOOL result = [packageInfoString writeToFile:[self getStatusFilePath]
                         atomically:YES
                           encoding:NSUTF8StringEncoding
                              error:error];
+
+    if (!result) {
+        return NO;
+    }
+    return YES;
 }
 
 @end