Fuzzing-related changes.

* More LOGICAL_ERROR
* Proper cloning of some Asts
* Field::safeGet for user-supplied values

src/Common/assert_cast.h

@@ -13,7 +13,7 @@ namespace DB
 {
     namespace ErrorCodes
     {
-        extern const int BAD_CAST;
+        extern const int LOGICAL_ERROR;
     }
 }
 
@@ -41,11 +41,11 @@ To assert_cast(From && from)
     }
     catch (const std::exception & e)
     {
-        throw DB::Exception(e.what(), DB::ErrorCodes::BAD_CAST);
+        throw DB::Exception(e.what(), DB::ErrorCodes::LOGICAL_ERROR);
     }
 
     throw DB::Exception("Bad cast from type " + demangle(typeid(from).name()) + " to " + demangle(typeid(To).name()),
-                        DB::ErrorCodes::BAD_CAST);
+                        DB::ErrorCodes::LOGICAL_ERROR);
 #else
     return static_cast<To>(from);
 #endif

src/Parsers/ASTColumnDeclaration.cpp

@@ -12,7 +12,9 @@ ASTPtr ASTColumnDeclaration::clone() const
 
     if (type)
     {
-        res->type = type;
+        // Type may be an ASTFunction (e.g. `create table t (a Decimal(9,0))`),
+        // so we have to clone it properly as well.
+        res->type = type->clone();
         res->children.push_back(res->type);
     }
 

src/Parsers/ASTExplainQuery.h

@@ -23,7 +23,13 @@ public:
 
     String getID(char delim) const override { return "Explain" + (delim + toString(kind)); }
     ExplainKind getKind() const { return kind; }
-    ASTPtr clone() const override { return std::make_shared<ASTExplainQuery>(*this); }
+    ASTPtr clone() const override
+    {
+        auto res = std::make_shared<ASTExplainQuery>(*this);
+        res->children.clear();
+        res->children.push_back(children[0]->clone());
+        return res;
+    }
 
 protected:
     void formatImpl(const FormatSettings & settings, FormatState & state, FormatStateStacked frame) const override

src/Storages/MergeTree/KeyCondition.cpp

@@ -843,7 +843,7 @@ bool KeyCondition::tryParseAtomFromAST(const ASTPtr & node, const Context & cont
             || const_value.getType() == Field::Types::Float64)
         {
             /// Zero in all types is represented in memory the same way as in UInt64.
-            out.function = const_value.get<UInt64>()
+            out.function = const_value.safeGet<UInt64>()
                 ? RPNElement::ALWAYS_TRUE
                 : RPNElement::ALWAYS_FALSE;
 

src/Storages/MergeTree/MergeTreeIndexFullText.cpp

@@ -785,13 +785,13 @@ std::unique_ptr<IMergeTreeIndex> bloomFilterIndexCreator(
             throw Exception("`ngrambf` index must have exactly 4 arguments.", ErrorCodes::INCORRECT_QUERY);
 
         size_t n = typeid_cast<const ASTLiteral &>(
-                *node->type->arguments->children[0]).value.get<size_t>();
+                *node->type->arguments->children[0]).value.safeGet<size_t>();
         size_t bloom_filter_size = typeid_cast<const ASTLiteral &>(
-                *node->type->arguments->children[1]).value.get<size_t>();
+                *node->type->arguments->children[1]).value.safeGet<size_t>();
         size_t bloom_filter_hashes = typeid_cast<const ASTLiteral &>(
-                *node->type->arguments->children[2]).value.get<size_t>();
+                *node->type->arguments->children[2]).value.safeGet<size_t>();
         size_t seed = typeid_cast<const ASTLiteral &>(
-                *node->type->arguments->children[3]).value.get<size_t>();
+                *node->type->arguments->children[3]).value.safeGet<size_t>();
 
         auto tokenizer = std::make_unique<NgramTokenExtractor>(n);
 
@@ -805,11 +805,11 @@ std::unique_ptr<IMergeTreeIndex> bloomFilterIndexCreator(
             throw Exception("`tokenbf` index must have exactly 3 arguments.", ErrorCodes::INCORRECT_QUERY);
 
         size_t bloom_filter_size = typeid_cast<const ASTLiteral &>(
-                *node->type->arguments->children[0]).value.get<size_t>();
+                *node->type->arguments->children[0]).value.safeGet<size_t>();
         size_t bloom_filter_hashes = typeid_cast<const ASTLiteral &>(
-                *node->type->arguments->children[1]).value.get<size_t>();
+                *node->type->arguments->children[1]).value.safeGet<size_t>();
         size_t seed = typeid_cast<const ASTLiteral &>(
-                *node->type->arguments->children[2]).value.get<size_t>();
+                *node->type->arguments->children[2]).value.safeGet<size_t>();
 
         auto tokenizer = std::make_unique<SplitTokenExtractor>();
 

src/Storages/MergeTree/MergeTreeIndexSet.cpp

@@ -468,7 +468,7 @@ std::unique_ptr<IMergeTreeIndex> setIndexCreator(
     if (!node->type->arguments || node->type->arguments->children.size() != 1)
         throw Exception("Set index must have exactly one argument.", ErrorCodes::INCORRECT_QUERY);
     else if (node->type->arguments->children.size() == 1)
-        max_rows = node->type->arguments->children[0]->as<ASTLiteral &>().value.get<size_t>();
+        max_rows = node->type->arguments->children[0]->as<ASTLiteral &>().value.safeGet<size_t>();
 
 
     ASTPtr expr_list = MergeTreeData::extractKeyExpressionList(node->expr->clone());