This corrects all violations of -Wzero-as-null-pointer-constant identified in the Qt codebase.
These changes are extracted from #15112 as suggested by @MarcoFalke to ease review. This is in service of enabling -Wzero-as-null-pointer-constant, which should eliminate this as a concern going forward.
Note there are 2 non-Qt changes: src/test/allocator_tests.cpp and src/wallet/db.cpp.
337@@ -338,7 +338,7 @@ bool BerkeleyBatch::VerifyEnvironment(const fs::path& file_path, std::string& er
338 BerkeleyEnvironment* env = GetWalletEnv(file_path, walletFile);
339 fs::path walletDir = env->Directory();
340
341- LogPrintf("Using BerkeleyDB version %s\n", DbEnv::version(0, 0, 0));
342+ LogPrintf("Using BerkeleyDB version %s\n", DbEnv::version(nullptr, nullptr, nullptr));
299@@ -300,8 +300,8 @@ QVariant AddressTableModel::headerData(int section, Qt::Orientation orientation,
300
301 Qt::ItemFlags AddressTableModel::flags(const QModelIndex &index) const
302 {
303- if(!index.isValid())
304- return 0;
305+ if (!index.isValid()) return Qt::NoItemFlags;
44@@ -45,7 +45,7 @@ class ShutdownWindow : public QWidget
45 Q_OBJECT
46
47 public:
48- explicit ShutdownWindow(QWidget *parent=0, Qt::WindowFlags f=0);
49+ explicit ShutdownWindow(QWidget *parent=nullptr, Qt::WindowFlags f=Qt::Widget);
@luke-jr The change @Empact is suggesting is not a code style change.
Reasons to use nullptr include:
nullptr has a well-specified (very restrictive) type, and thus works in more scenarios where type deduction might do the wrong thing on NULL or 0.nullptr cannot be confused with an int.Enabling -Wzero-as-null-pointer-constant will help developers follow our developer guide which is a good thing. This in turn means that human reviewers will not have to point out the benefits of nullptr ever again :-)
Concept ACK, agree it improves code.
I don’t think this should be merged without something to prevent more zero-as-null-pointer.
I don’t think this should be merged without something to prevent more zero-as-null-pointer.
I agree, as discussed many times, we don’t want PR after PR fixing ‘straggler’ occurrences. It’s not that important that it warrants some kind of crusade.
But if #15112 enables failing the build on this I’m okay with that and they should probably be merged together.
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Reviewers, this pull request conflicts with the following ones:
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Qt-only changes.
Also used type-appropriate enum values such as Qt::NoItemFlags in
some cases.
All cases identified via -Wzero-as-null-pointer-constant