Merge #2374: [Backport] Fix memory leaks in qt/guiutil.cpp

aad1362 scripted-diff: Replace 'NULL' with 'nullptr' in guiutil.cpp (random-zebra)
5c07620 Fix memory leaks in qt/guiutil.cpp (Dan Raviv)

Pull request description:

  From bitcoin#11156

  > on macOS:
  > listSnapshot was leaking in findStartupItemInList()
  > bitcoinAppUrl was leaking in [Get|Set]StartOnSystemStartup()

ACKs for top commit:
  Fuzzbawls:
    utACK aad1362
  furszy:
    utACK aad1362 and merging..

Tree-SHA512: 640714832bed4513d14875294175085b30d1473dc3497e247959863867f743abe926cf6ba18bb42982e81906bf741b1c86c0953bad742f6e0772467ae7d6f0c1

src/qt/guiutil.cpp

@@ -651,7 +651,7 @@ bool SetStartOnSystemStartup(bool fAutoStart)
     fs::remove(StartupShortcutPath());
 
     if (fAutoStart) {
-        CoInitialize(NULL);
+        CoInitialize(nullptr);
 
         // Get a pointer to the IShellLink interface.
         IShellLinkW* psl = nullptr;
@@ -773,57 +773,76 @@ bool SetStartOnSystemStartup(bool fAutoStart)
 LSSharedFileListItemRef findStartupItemInList(LSSharedFileListRef list, CFURLRef findUrl);
 LSSharedFileListItemRef findStartupItemInList(LSSharedFileListRef list, CFURLRef findUrl)
 {
+    CFArrayRef listSnapshot = LSSharedFileListCopySnapshot(list, nullptr);
+    if (listSnapshot == nullptr) {
+        return nullptr;
+    }
+
     // loop through the list of startup items and try to find the pivx app
-    CFArrayRef listSnapshot = LSSharedFileListCopySnapshot(list, NULL);
     for (int i = 0; i < CFArrayGetCount(listSnapshot); i++) {
         LSSharedFileListItemRef item = (LSSharedFileListItemRef)CFArrayGetValueAtIndex(listSnapshot, i);
         UInt32 resolutionFlags = kLSSharedFileListNoUserInteraction | kLSSharedFileListDoNotMountVolumes;
-        CFURLRef currentItemURL = NULL;
+        CFURLRef currentItemURL = nullptr;
 
 #if defined(MAC_OS_X_VERSION_MAX_ALLOWED) && MAC_OS_X_VERSION_MAX_ALLOWED >= 10100
     if (&LSSharedFileListItemCopyResolvedURL)
-        currentItemURL = LSSharedFileListItemCopyResolvedURL(item, resolutionFlags, NULL);
+        currentItemURL = LSSharedFileListItemCopyResolvedURL(item, resolutionFlags, nullptr);
 #if defined(MAC_OS_X_VERSION_MIN_REQUIRED) && MAC_OS_X_VERSION_MIN_REQUIRED < 10100
     else
-        LSSharedFileListItemResolve(item, resolutionFlags, &currentItemURL, NULL);
+        LSSharedFileListItemResolve(item, resolutionFlags, &currentItemURL, nullptr);
 #endif
 #else
-    LSSharedFileListItemResolve(item, resolutionFlags, &currentItemURL, NULL);
+    LSSharedFileListItemResolve(item, resolutionFlags, &currentItemURL, nullptr);
 #endif
 
-        if (currentItemURL && CFEqual(currentItemURL, findUrl)) {
-            // found
-            CFRelease(currentItemURL);
-            return item;
-        }
         if (currentItemURL) {
+            if (CFEqual(currentItemURL, findUrl)) {
+                // found
+                CFRelease(listSnapshot);
+                CFRelease(currentItemURL);
+                return item;
+            }
             CFRelease(currentItemURL);
         }
     }
-    return NULL;
+
+    CFRelease(listSnapshot);
+    return nullptr;
 }
 
 bool GetStartOnSystemStartup()
 {
     CFURLRef bitcoinAppUrl = CFBundleCopyBundleURL(CFBundleGetMainBundle());
-    LSSharedFileListRef loginItems = LSSharedFileListCreate(NULL, kLSSharedFileListSessionLoginItems, NULL);
+    if (bitcoinAppUrl == nullptr) {
+        return false;
+    }
+
+    LSSharedFileListRef loginItems = LSSharedFileListCreate(nullptr, kLSSharedFileListSessionLoginItems, nullptr);
     LSSharedFileListItemRef foundItem = findStartupItemInList(loginItems, bitcoinAppUrl);
+
+    CFRelease(bitcoinAppUrl);
     return !!foundItem; // return boolified object
 }
 
 bool SetStartOnSystemStartup(bool fAutoStart)
 {
     CFURLRef bitcoinAppUrl = CFBundleCopyBundleURL(CFBundleGetMainBundle());
-    LSSharedFileListRef loginItems = LSSharedFileListCreate(NULL, kLSSharedFileListSessionLoginItems, NULL);
+    if (bitcoinAppUrl == nullptr) {
+        return false;
+    }
+
+    LSSharedFileListRef loginItems = LSSharedFileListCreate(nullptr, kLSSharedFileListSessionLoginItems, nullptr);
     LSSharedFileListItemRef foundItem = findStartupItemInList(loginItems, bitcoinAppUrl);
 
     if (fAutoStart && !foundItem) {
         // add pivx app to startup item list
-        LSSharedFileListInsertItemURL(loginItems, kLSSharedFileListItemBeforeFirst, NULL, NULL, bitcoinAppUrl, NULL, NULL);
+        LSSharedFileListInsertItemURL(loginItems, kLSSharedFileListItemBeforeFirst, nullptr, nullptr, bitcoinAppUrl, nullptr, nullptr);
     } else if (!fAutoStart && foundItem) {
         // remove item
         LSSharedFileListItemRemove(loginItems, foundItem);
     }
+
+    CFRelease(bitcoinAppUrl);
     return true;
 }
 #pragma GCC diagnostic pop