Better fix

programs/local/LocalServer.cpp

@@ -130,11 +130,6 @@ void applySettingsOverridesForLocal(ContextMutablePtr context)
     context->setSettings(settings);
 }
 
-LocalServer::LocalServer()
-{
-    is_local = true;
-}
-
 Poco::Util::LayeredConfiguration & LocalServer::getClientConfiguration()
 {
     return config();

programs/local/LocalServer.h

@@ -23,7 +23,7 @@ namespace DB
 class LocalServer : public ClientApplicationBase, public Loggers
 {
 public:
-    LocalServer();
+    LocalServer() = default;
 
     void initialize(Poco::Util::Application & self) override;
 

src/Client/ClientBase.cpp

@@ -1630,6 +1630,11 @@ void ClientBase::sendData(Block & sample, const ColumnsDescription & columns_des
     if (!parsed_insert_query)
         return;
 
+    /// If it's clickhouse-local, and the input data reading is already baked into the query pipeline,
+    /// don't read the data again here.
+    if (!connection->isSendDataNeeded())
+        return;
+
     bool have_data_in_stdin = !is_interactive && !stdin_is_a_tty && isStdinNotEmptyAndValid(std_in);
 
     if (need_render_progress)
@@ -1748,7 +1753,6 @@ void ClientBase::sendData(Block & sample, const ColumnsDescription & columns_des
     }
     else if (!is_interactive)
     {
-        if (!is_local)
         sendDataFromStdin(sample, columns_description_for_query, parsed_query);
     }
     else

src/Client/ClientBase.h

@@ -263,8 +263,6 @@ protected:
     bool is_interactive = false; /// Use either interactive line editing interface or batch mode.
     bool delayed_interactive = false;
 
-    bool is_local = false; /// clickhouse-local, otherwise clickhouse-client
-
     bool echo_queries = false; /// Print queries before execution in batch mode.
     bool ignore_error = false; /// In case of errors, don't print error message, continue to next query. Only applicable for non-interactive mode.
 

src/Client/IServerConnection.h

@@ -109,6 +109,10 @@ public:
     /// Send block of data; if name is specified, server will write it to external (temporary) table of that name.
     virtual void sendData(const Block & block, const String & name, bool scalar) = 0;
 
+    /// Whether the client needs to read and send the data for the INSERT.
+    /// False if the server will read the data through other means (in particular if clickhouse-local added input reading step directly into the query pipeline).
+    virtual bool isSendDataNeeded() const { return true; }
+
     /// Send all contents of external (temporary) tables.
     virtual void sendExternalTablesData(ExternalTablesData & data) = 0;
 

src/Client/LocalConnection.cpp

@@ -328,6 +328,11 @@ void LocalConnection::sendData(const Block & block, const String &, bool)
         sendProfileEvents();
 }
 
+bool LocalConnection::isSendDataNeeded() const
+{
+    return !state || state->input_pipeline == nullptr;
+}
+
 void LocalConnection::sendCancel()
 {
     state->is_cancelled = true;

src/Client/LocalConnection.h

@@ -120,6 +120,8 @@ public:
 
     void sendData(const Block & block, const String & name/* = "" */, bool scalar/* = false */) override;
 
+    bool isSendDataNeeded() const override;
+
     void sendExternalTablesData(ExternalTablesData &) override;
 
     void sendMergeTreeReadTaskResponse(const ParallelReadResponse & response) override;

tests/queries/0_stateless/03031_clickhouse_local_input.reference

@@ -9,3 +9,7 @@ bar
 bam
 # inferred destination table structure
 foo
+# direct
+foo
+# infile
+foo

tests/queries/0_stateless/03031_clickhouse_local_input.sh

@@ -32,4 +32,12 @@ echo '# inferred destination table structure'
 $CLICKHOUSE_LOCAL --engine_file_truncate_on_insert=1 -q "insert into function file('$tmp_file', 'TSV') select * from input('x String') format LineAsString" <"$tmp_input"
 cat "$tmp_file"
 
+echo '# direct'
+$CLICKHOUSE_LOCAL --engine_file_truncate_on_insert=1 -q "insert into function file('$tmp_file', 'LineAsString', 'x String') format LineAsString" <"$tmp_input"
+cat "$tmp_file"
+
+echo '# infile'
+$CLICKHOUSE_LOCAL --engine_file_truncate_on_insert=1 -q "insert into function file('$tmp_file', 'LineAsString', 'x String') from infile '$tmp_input' format LineAsString"
+cat "$tmp_file"
+
 rm -f "${tmp_file:?}" "${tmp_input:?}"