Fix segfault in arrayExists AST optimization

src/Interpreters/RewriteArrayExistsFunctionVisitor.cpp

@@ -2,6 +2,7 @@
 #include <Parsers/ASTFunction.h>
 #include <Parsers/ASTIdentifier.h>
 #include <Parsers/ASTLiteral.h>
+#include <Parsers/ASTTablesInSelectQuery.h>
 
 namespace DB
 {
@@ -76,4 +77,22 @@ void RewriteArrayExistsFunctionMatcher::visit(const ASTFunction & func, ASTPtr &
     }
 }
 
+bool RewriteArrayExistsFunctionMatcher::needChildVisit(const ASTPtr & ast, const ASTPtr & child)
+{
+    /// SELECT ... JOIN ... ON arrayExists(x -> x = 1, arr)
+    /// A JOIN on expression is invalid, ignore it to avoid segmentation fault
+
+    if (auto * join = ast->as<ASTTableJoin>())
+    {
+        if (auto * func = child->as<ASTFunction>())
+        {
+            if (func->name == "arrayExists")
+                return false;
+        }
+    }
+
+    return true;
+}
+
+
 }

src/Interpreters/RewriteArrayExistsFunctionVisitor.h

@@ -18,7 +18,7 @@ public:
 
     static void visit(ASTPtr & ast, Data &);
     static void visit(const ASTFunction &, ASTPtr & ast, Data &);
-    static bool needChildVisit(const ASTPtr &, const ASTPtr &) { return true; }
+    static bool needChildVisit(const ASTPtr & ast, const ASTPtr & child);
 };
 
 using RewriteArrayExistsFunctionVisitor = InDepthNodeVisitor<RewriteArrayExistsFunctionMatcher, false>;

tests/queries/0_stateless/02834_array_exists_segfault.sql

@@ -0,0 +1,2 @@
+CREATE TABLE 02834_t (id UInt64, arr Array(UInt64)) ENGINE = MergeTree ORDER BY id;
+WITH subquery AS (SELECT []) SELECT t.* FROM 02834_t AS t JOIN subquery ON arrayExists(x -> x = 1, t.arr); -- { serverError INVALID_JOIN_ON_EXPRESSION }