fix a bug in projections

src/Storages/MergeTree/IMergeTreeDataPart.cpp

@@ -312,15 +312,20 @@ IMergeTreeDataPart::IMergeTreeDataPart(
     const IMergeTreeDataPart * parent_part_)
     : DataPartStorageHolder(data_part_storage_)
     , storage(storage_)
-    , name(name_)
+    , mutable_name(name_)
+    , name(mutable_name)
     , info(info_)
     , index_granularity_info(storage_, part_type_)
     , part_type(part_type_)
     , parent_part(parent_part_)
+    , parent_part_name(parent_part ? parent_part->name : "")
     , use_metadata_cache(storage.use_metadata_cache)
 {
     if (parent_part)
+    {
+        chassert(parent_part_name.starts_with(parent_part->info.partition_id));     /// Make sure there's no prefix
         state = MergeTreeDataPartState::Active;
+    }
 
     incrementStateMetric(state);
     incrementTypeMetric(part_type);
@@ -337,6 +342,12 @@ IMergeTreeDataPart::~IMergeTreeDataPart()
     decrementTypeMetric(part_type);
 }
 
+void IMergeTreeDataPart::setName(const String & new_name)
+{
+    mutable_name = new_name;
+    for (auto & proj_part : projection_parts)
+        proj_part.second->parent_part_name = new_name;
+}
 
 String IMergeTreeDataPart::getNewName(const MergeTreePartInfo & new_part_info) const
 {

src/Storages/MergeTree/IMergeTreeDataPart.h

@@ -200,9 +200,14 @@ public:
     /// If token is not empty, block id is calculated based on it instead of block data
     String getZeroLevelPartBlockID(std::string_view token) const;
 
+    void setName(const String & new_name);
+
     const MergeTreeData & storage;
 
-    String name;
+private:
+    String mutable_name;
+public:
+    const String & name;    // const ref to private mutable_name
     MergeTreePartInfo info;
 
     /// Part unique identifier.
@@ -386,6 +391,7 @@ public:
     bool isProjectionPart() const { return parent_part != nullptr; }
 
     const IMergeTreeDataPart * getParentPart() const { return parent_part; }
+    String getParentPartName() const { return parent_part_name; }
 
     const std::map<String, std::shared_ptr<IMergeTreeDataPart>> & getProjectionParts() const { return projection_parts; }
 
@@ -519,6 +525,7 @@ protected:
 
     /// Not null when it's a projection part.
     const IMergeTreeDataPart * parent_part;
+    String parent_part_name;
 
     std::map<String, std::shared_ptr<IMergeTreeDataPart>> projection_parts;
 

src/Storages/MergeTree/MergeTreeData.cpp

@@ -7455,7 +7455,19 @@ void MergeTreeData::reportBrokenPart(MergeTreeData::DataPartPtr data_part) const
         return;
 
     if (data_part->isProjectionPart())
-        data_part = data_part->getParentPart()->shared_from_this();
+    {
+        String parent_part_name = data_part->getParentPartName();
+        auto parent_part = getPartIfExists(parent_part_name, {DataPartState::PreActive, DataPartState::Active, DataPartState::Outdated});
+
+        if (!parent_part)
+        {
+            LOG_WARNING(log, "Did not find parent part {} for potentially broken projection part {}",
+                        parent_part_name, data_part->getDataPartStorage().getFullPath());
+            return;
+        }
+
+        data_part = parent_part;
+    }
 
     if (data_part->getDataPartStorage().isBroken())
     {

src/Storages/MergeTree/MutateTask.cpp

@@ -917,7 +917,7 @@ public:
             {
                 LOG_DEBUG(log, "Merged a projection part in level {}", current_level);
                 selected_parts[0]->renameTo(projection.name + ".proj", true);
-                selected_parts[0]->name = projection.name;
+                selected_parts[0]->setName(projection.name);
                 selected_parts[0]->is_temp = false;
                 ctx->new_data_part->addProjectionPart(name, std::move(selected_parts[0]));
 

src/Storages/MergeTree/ReplicatedMergeTreeSink.cpp

@@ -788,7 +788,7 @@ std::pair<std::vector<String>, bool> ReplicatedMergeTreeSinkImpl<async_insert>::
             part->info.level = 0;
             part->info.mutation = 0;
 
-            part->name = part->getNewName(part->info);
+            part->setName(part->getNewName(part->info));
 
             StorageReplicatedMergeTree::LogEntry log_entry;
 
@@ -914,7 +914,7 @@ std::pair<std::vector<String>, bool> ReplicatedMergeTreeSinkImpl<async_insert>::
             /// Note that it may also appear on filesystem right now in PreActive state due to concurrent inserts of the same data.
             /// It will be checked when we will try to rename directory.
 
-            part->name = existing_part_name;
+            part->setName(existing_part_name);
             part->info = MergeTreePartInfo::fromPartName(existing_part_name, storage.format_version);
             /// Used only for exception messages.
             block_number = part->info.min_block;

src/Storages/StorageMergeTree.cpp

@@ -2260,7 +2260,7 @@ void StorageMergeTree::fillNewPartName(MutableDataPartPtr & part, DataPartsLock
 {
     part->info.min_block = part->info.max_block = increment.get();
     part->info.mutation = 0;
-    part->name = part->getNewName(part->info);
+    part->setName(part->getNewName(part->info));
 }
 
 }

src/Storages/StorageReplicatedMergeTree.cpp

@@ -9262,7 +9262,7 @@ bool StorageReplicatedMergeTree::createEmptyPartInsteadOfLost(zkutil::ZooKeeperP
     }
 
     MergeTreeData::MutableDataPartPtr new_data_part = createEmptyPart(new_part_info, partition, lost_part_name, NO_TRANSACTION_PTR);
-    new_data_part->name = lost_part_name;
+    new_data_part->setName(lost_part_name);
 
     try
     {